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1.
Addict Behav ; 151: 107934, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38101120

RESUMO

Previous research has suggested that individuals who smoke demonstrate a behavioral tendency to approach rather than avoid smoking-related stimuli (i.e., approach bias). This study assessed whether 149 undergraduates with varying levels of e-cigarette use demonstrated an approach bias for vaping-related stimuli on an Approach-Avoidance Task (AAT). In contrast to our hypotheses, participants with e-cigarette use demonstrated a significant avoidance bias to vaping-related stimuli, and this effect appeared to be primarily driven by female e-cigarette users. Further, we found that more severe e-cigarette use was associated with numerous adverse outcomes, including reduced quality of life and increased vaping cravings, depressive symptoms, perceived stress, and cannabis use severity. Overall, our findings elucidate various negative impacts of e-cigarette use and suggest a potential role for sex differences in approach-avoidance tendencies toward vaping-related stimuli among young adults.


Assuntos
Sistemas Eletrônicos de Liberação de Nicotina , Produtos do Tabaco , Vaping , Adulto Jovem , Humanos , Masculino , Feminino , Vaping/efeitos adversos , Qualidade de Vida , Viés , Estudantes , Eletrônica
2.
Behav Brain Res ; 438: 114176, 2023 02 13.
Artigo em Inglês | MEDLINE | ID: mdl-36283566

RESUMO

This study examined whether a conditioned place preference (CPP) could be established for a virtual reality (VR) room that previously contained virtual alcohol stimuli. 298 undergraduates with varying levels of alcohol use completed six, three-minute conditioning sessions in which they were confined to one of two visually-distinct VR rooms: one of the VR rooms contained virtual alcohol cues (CS+) while the other VR room was neutral (CS-). Following conditioning, participants completed a three-minute test session during which they had unrestricted access to both VR rooms and neither room contained any alcohol-related cues. Although no virtual alcohol cues were present, participants with alcohol use (n = 248) spent significantly longer in CS+ relative to CS- compared to participants with alcohol non-use (n = 50) during the test session. This is the first study to show that a CPP can be established using virtual alcohol cues, in the absence of any actual alcohol administration. However, participants with alcohol use did not subjectively report enjoying CS+ more than CS- and explicitly chose CS- as their preferred room. Interestingly, these findings suggest that implicit and explicit measures of CPP may tap into distinct, separable processes and should be investigated further.


Assuntos
Sinais (Psicologia) , Realidade Virtual , Humanos , Condicionamento Clássico , Consumo de Bebidas Alcoólicas , Estudantes , Etanol
3.
Exp Clin Psychopharmacol ; 31(2): 464-474, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36074627

RESUMO

Nicotine has been shown to facilitate hippocampal-dependent context fear conditioning (FC), but not hippocampal-independent delay cued fear conditioning. Studies examining the effects of nicotine on learned fear have been exclusively limited to nonhumans. The present study aimed to translate nonhuman findings by investigating the effects of nicotine on cued and context fear in humans using a virtual reality (VR) analog of the fear conditioning task. Sixty-seven nicotine-using undergraduates were randomly assigned to receive either a 2 mg nicotine or placebo lozenge prior to conditioning. During conditioning, participants were confined to a virtual room and were conditioned to green floodlight presentations (conditioned stimulus [CS +]) paired with a wrist shock (unconditioned stimulus [US]). A red floodlight served as the CS- during which no shock occurred. Delay cued and context fear testing immediately followed conditioning. Physiological skin conductance responses (SCRs) were recorded continuously throughout all sessions. Nicotine enhanced context fear conditioning such that SCRs to the shock-paired context were significantly greater for the nicotine group than the placebo group. Nicotine did not enhance delay cued fear. Exploratory analyses examining the relationship between fear conditioning and self-reported anxiety revealed that relative to those with lower levels of trait anxiety, nicotine-treated individuals with higher trait anxiety levels were less likely to demonstrate differential conditioning to the shock-paired cue. These findings support abundant nonhuman literature indicating that nicotine facilitates hippocampus-dependent versions of fear conditioning in humans. Results also suggest a role for dysregulated safety learning in pathological anxiety, which may be exacerbated by nicotine use. (PsycInfo Database Record (c) 2023 APA, all rights reserved).


Assuntos
Sinais (Psicologia) , Nicotina , Humanos , Ansiedade , Condicionamento Clássico , Medo , Nicotina/farmacologia
4.
J Addict Dis ; 40(4): 489-500, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35356853

RESUMO

Individuals with addictions often exhibit approach bias, or the relatively automatic action tendency to approach rather than avoid addiction-related stimuli. The current study used a cannabis-Approach-Avoidance Task (AAT) to assess approach-avoidance tendencies toward cannabis stimuli among 211 undergraduate college students with varying levels of cannabis use. Frequency and severity of cannabis use was assessed using the Cannabis Use Disorder Identification Test - Short Form (CUDIT-R). The sample did not demonstrate a significant approach or avoidance bias toward cannabis stimuli; instead, participants were significantly slower to approach and avoid cannabis stimuli relative to neutral stimuli. Individuals with problematic cannabis use who met criteria for a possible cannabis use disorder (CUD) based on CUDIT-R criteria were significantly slower to avoid but not to approach cannabis stimuli compared to individuals with nonuse and non-problematic use. Moreover, increased frequency and severity of cannabis use was significantly associated with increased reaction times to avoid cannabis stimuli. Findings appear to differ from some previous studies examining approach-avoidance tendencies toward cannabis, suggesting that the role of cognitive biases in cannabis use is complex and should be further investigated.


Assuntos
Comportamento Aditivo , Cannabis , Abuso de Maconha , Transtornos Relacionados ao Uso de Substâncias , Comportamento Aditivo/psicologia , Humanos , Abuso de Maconha/psicologia , Tempo de Reação , Universidades
5.
Behav Brain Res ; 417: 113592, 2022 01 24.
Artigo em Inglês | MEDLINE | ID: mdl-34560131

RESUMO

To examine the role of estradiol in hippocampal-dependent spatial memory in women, 86 female undergraduates were tested in a virtual Morris water task (VMWT), a virtual radial arm maze (VRAM), and a mental rotation task (MRT) within a single daily session. The VMWT and RAM were also administered 24 h later to examine the effects of estradiol on memory consolidation. Women on oral contraceptives (OCs) or those who were naturally cycling and exhibited low estradiol (LE) or high estradiol (HE), as determined by salivary assays, were included. At the start of day two, the HE group showed superior spatial reference memory on the VMWT relative to the LE group, as evidenced by significantly shorter distances navigating to the hidden platform. The LE group also had the poorest probe trial performance at the start of day two compared to both other groups. There were no group differences in performance on the RAM or MRT. These results provide support for estradiol's role in the consolidation of spatial reference memory in women, and emphasize the differential sensitivities of various virtual memory tasks in assessing spatial memory function in women.


Assuntos
Estradiol/farmacologia , Teste do Labirinto Aquático de Morris/efeitos dos fármacos , Memória Espacial/fisiologia , Realidade Virtual , Adulto , Feminino , Hipocampo/efeitos dos fármacos , Humanos , Aprendizagem em Labirinto/efeitos dos fármacos , Rememoração Mental , Percepção Espacial/efeitos dos fármacos , Adulto Jovem
6.
Subst Use Misuse ; 55(13): 2156-2164, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32720546

RESUMO

BACKGROUND: Nicotine has recently been shown to enhance the motivational value of non-nicotine stimuli in nonhumans. To investigate whether nicotine also enhances reward in humans, we used a virtual translation of the conditioned place preference (CPP) paradigm to examine nicotine's reward-enhancing effects using a low-dose 2 mg nicotine lozenge targeted to a mild use population. Methods: Sixty-eight nicotine-using undergraduates were randomly assigned to receive either a 2 mg nicotine or placebo lozenge prior to conditioning. During each of six, three-minute conditioning sessions, participants were confined to one of two VR rooms. In one room, they received real chocolate M&Ms, whereas no M&Ms were administered in the other room. Following conditioning, a three-minute free-access test session occurred during which participants had unrestricted access to both rooms without reward. Results: Individuals who received nicotine demonstrated a CPP by spending significantly more time in the room previously paired with M&Ms compared to the unrewarded room (p = 0.04). Those who received placebo did not demonstrate a CPP (p > 0.05). Moreover, we observed no significant differences between treatment groups in terms of the amount of time spent in each virtual room. Conclusion: While nicotine seems to facilitate CPP expression for a virtual environment previously paired with chocolate food rewards, further characterization of the mechanism by which this occurs is needed.


Assuntos
Condicionamento Psicológico , Nicotina , Alimentos , Humanos , Recompensa , Estudantes
7.
Addict Behav ; 108: 106438, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32325387

RESUMO

Repeated engagement in addictive behaviors may lead to relatively automatic action tendencies whereby individuals approach rather than avoid addictive stimuli. This study assessed whether an approach bias for erotic stimuli exists among heterosexual college-aged females who report using pornography. We tested 121 female undergraduates using an approach-avoidance task (AAT) employing both erotic and neutral stimuli, during which participants were instructed to push or pull a gaming joystick in response to image orientation. To simulate approach and avoidance movements, pulling the joystick enlarged the image and pushing shrunk the image. Severity of pornography use was assessed using the Brief Pornography Screener (BPS) and the Problematic Pornography Use Scale (PPUS). Participants demonstrated a significant approach bias of 24.81 ms for erotic stimuli as compared to neutral stimuli, and this approach bias significantly positively correlated with PPUS scores. Moreover, approach bias scores were significantly positively correlated with anhedonia (as assessed by the Snaith-Hamilton Pleasure Scale), indicating that the stronger the degree of approach for erotic stimuli, the more anhedonia that was observed. Anhedonia was not significantly associated with pornography use severity, however. Findings implicate both similarities and differences in problematic pornography use among female and male users. A limitation of the current study is that it assessed approach biases among only heterosexual females due to the erotic stimuli employed during the AAT. Future studies should examine approach biases among females of varying sexual orientations.


Assuntos
Comportamento Aditivo , Literatura Erótica , Viés , Feminino , Heterossexualidade , Humanos , Masculino , Estudantes , Adulto Jovem
8.
J Behav Addict ; 8(2): 234-241, 2019 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-31257916

RESUMO

BACKGROUND AND AIMS: Addicted individuals often demonstrate relatively automatic action tendencies in response to addiction-related stimuli, whereby they approach rather than avoid addictive stimuli. This study assessed whether an approach bias for erotic stimuli exists among heterosexual college-aged males who report using pornography. METHODS: We tested 72 male undergraduate students using an approach-avoidance task employing erotic stimuli, during which participants were instructed to push or pull a joystick in response to image orientation. To simulate approach and avoidance movements, pulling the joystick enlarged the image and pushing shrunk the image. Frequency and severity of pornography use was assessed using a Brief Pornography Screener and the Problematic Pornography Use Scale (PPUS). RESULTS: Participants demonstrated a significant approach bias for erotic stimuli as compared to neutral stimuli, and this approach bias significantly correlated with pornography-use measures. Moreover, individuals with problematic pornography use (as classified by the PPUS) showed more than double the approach bias than did non-problematic users. DISCUSSION AND CONCLUSION: The observation of cognitive biases for erotic stimuli in individuals with problematic pornography use indicate similarities between behavioral and substance addictions.


Assuntos
Comportamento Aditivo/diagnóstico , Comportamento Aditivo/psicologia , Comportamento de Escolha , Literatura Erótica/psicologia , Heterossexualidade/psicologia , Inquéritos e Questionários , Adulto , Viés , Humanos , Masculino , Estudantes/psicologia , Estudantes/estatística & dados numéricos , Universidades , Adulto Jovem
9.
Drug Alcohol Depend ; 201: 236-243, 2019 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-31254750

RESUMO

BACKGROUND: Quantity and frequency of drinking may be used to effectively quantify the severity of alcohol-use. Drinking-severity has been related to neurocognitive impairments in such domains as spatial working memory (SWM). Youth drinking has been associated with altered neurofunctional underpinnings of SWM. The current study examined the relationship between drinking-severity and SWM processing. METHODS: One-hundred-and-seventy college drinkers reported the maximum number of drinks in a 24 -h period in the last six-months (quantity) and average number of drinking weeks in the last six-months (frequency). All participants performed a virtual Morris Water Task during fMRI which included trials where the target platform was visible or hidden. RESULTS: Greater quantity was associated with reduced SWM-related activity in the dorsolateral prefrontal cortex (F(1, 167) = 4.15, p = .04). Greater frequency was associated with reduced SWM-related activity in the hippocampus (F(1, 167) = 4.34, p = 0.039). Greater quantity was associated with longer search times (r = 0.21, p = .005) and greater platforms found (r = 0.19, p = .01) in VISIBLE trials. We did not find a relationship between drinking quantity or frequency and gender on SWM-related activity, although men found more platforms in both HIDDEN (F(1, 168) = 11.7, p = 0.0008) and VISIBLE (F(1, 168) = 23.0, p < .0001) trials compared to women. CONCLUSIONS: Altered SWM-related hippocampal function relating to alcohol use in young adults raises questions regarding the impact on young adult health and the nature of the findings. Future studies should examine whether these differences may lead to cognitive deficits later in life.


Assuntos
Consumo de Álcool na Faculdade/psicologia , Hipocampo/diagnóstico por imagem , Hipocampo/fisiologia , Memória de Curto Prazo/fisiologia , Navegação Espacial/fisiologia , Estudantes/psicologia , Adolescente , Bebidas Alcoólicas/efeitos adversos , Cognição/efeitos dos fármacos , Cognição/fisiologia , Feminino , Hipocampo/efeitos dos fármacos , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Memória de Curto Prazo/efeitos dos fármacos , Navegação Espacial/efeitos dos fármacos , Universidades/tendências , Adulto Jovem
10.
Addict Behav ; 77: 51-58, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28957728

RESUMO

Nicotine has been shown to enhance the reinforcement and reward-responsiveness of non-nicotine stimuli. To determine whether nicotine enhances the strength of conditioning to context, undergraduate participants with varying levels of nicotine dependence were recruited for a two-day study and tested on a virtual reality (VR) conditioned place preference (CPP) paradigm. On day one, participants explored two virtual rooms where they received multiple pairings of M&M rewards in one room and no rewards in the other room, followed by a free-access test session with no rewards. On day two, participants received three test sessions to assess extinction. Subsequently, participants received M&Ms. in a novel context and were then tested for reinstatement. Prior to testing on each day, subjects were administered either nicotine (4mg) or placebo lozenges, in a between-subjects, four-group, 2×2 design (nicotine or placebo on days 1 and 2). After conditioning on day one, only participants who received placebo exhibited a CPP by spending significantly more time in the room previously-paired with M&Ms. Contrary to our hypothesis, nicotine-treated participants did not display a significant CPP, and there were no significant differences between treatment groups. However, post hoc analysis indicated that in a subset of participants with greater nicotine dependence, the nicotine group displayed a CPP by rating the M&M-paired room as significantly more enjoyable than those who received placebo. Additionally, while neither treatment group showed significant place preferences during the first two extinction sessions on Day 2, individuals who received nicotine on Day 1 or placebo on Day 2 spent significantly more time in the M&M-paired room during the final extinction session. Finally, those who received nicotine on Day 2 exhibited significantly greater reinstatement compared to placebo-treated participants. These results partially support preclinical evidence that nicotine can affect learning, extinction, and reinstatement.


Assuntos
Condicionamento Psicológico/efeitos dos fármacos , Extinção Psicológica/efeitos dos fármacos , Estimulantes Ganglionares/farmacologia , Nicotina/farmacologia , Recompensa , Tabagismo/psicologia , Adulto , Doces , Connecticut , Feminino , Humanos , Masculino , Estudantes/psicologia , Estudantes/estatística & dados numéricos , Universidades
11.
Behav Brain Res ; 322(Pt A): 110-114, 2017 03 30.
Artigo em Inglês | MEDLINE | ID: mdl-28108321

RESUMO

Computerized tasks based on conditioned place preference (CPP) methodology offer the opportunity to study learning mechanisms involved in conditioned reward in humans. In this study, we examined acquisition and extinction of a CPP for virtual environments associated with monetary reward ($). Healthy men and women (N=57) completed a computerized CPP task in which they controlled an avatar within a virtual environment. On day 1, subjects completed 6 conditioning trials in which one room was paired with high $ and another with low $. Acquisition of place conditioning was assessed by measuring the time spent in each room during an exploration test of the virtual environments and using self-reported ratings of room liking and preference. Twenty-four hours later, retention and extinction of CPP were assessed during 4 successive exploration tests of the virtual environments. Participants exhibited a place preference for (spent significantly more time in) the virtual room paired with high $ over the one paired with low $ (p=0.015). They also reported that they preferred the high $ room (p<0.001) and liked it significantly more than the low $ room (p<0.001). However, these preferences were short-lived: 24h later subjects did not exhibit a behavioral or subjective preference for the high $ room. These findings show that individuals exhibit transient behavioral and subjective preferences for a virtual environment paired with monetary reward. Variations on this task may be useful to study mechanisms and brain substrates involved in conditioned reward and to examine the influence of drugs upon appetitive conditioning.


Assuntos
Condicionamento Psicológico , Recompensa , Percepção Espacial , Realidade Virtual , Adolescente , Adulto , Análise de Variância , Extinção Psicológica , Feminino , Humanos , Masculino , Memória , Pessoa de Meia-Idade , Testes Psicológicos , Comportamento Espacial , Adulto Jovem
12.
Behav Brain Res ; 308: 236-43, 2016 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-27108050

RESUMO

The current study examined sex differences in initial and subsequent strategies in solving a navigational problem within a virtual reality environment. We tested 163 undergraduates on a virtual T-maze task that included probe trials designed to assess whether participants were responding using either a place or response strategy. Participants were also tested on a mental rotation task and memory of the details of the virtual room. There were no differences between the sexes in copying or recalling a map of the room or on first trial performance of the T-maze. However, at trial two, males show a significant advantage in solving the task, and approximately 80% of the males adopt a place strategy to solve the T-maze whereas females at that point showed no strategy preference. Across all testing, both males and females preferentially used a place strategy. We discuss how factors such as spatial priming affect strategy preferences and how such factors may differentially affect males and females.


Assuntos
Resolução de Problemas/fisiologia , Interface Usuário-Computador , Análise de Variância , Feminino , Humanos , Masculino , Aprendizagem em Labirinto , Processos Mentais , Reconhecimento Psicológico/fisiologia , Fatores Sexuais , Navegação Espacial/fisiologia , Inquéritos e Questionários , Adulto Jovem
13.
Behav Brain Res ; 297: 15-9, 2016 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-26439185

RESUMO

The goal of this experiment was to examine whether a conditioned place preference could be established in humans using a secondary reinforcer that provided little obvious reward to the participants. Two experiments were conducted to answer this question. In Experiment 1, 244 undergraduates were placed into a VR environment consisting of two visually distinct rooms connected by a door. Throughout the experiment, one room was randomly paired with occasional point rewards while the other unique room was never paired with rewards. Participants received thee pairings in each room. After a short break, a test session was administered, and participants were given free access to the entire VR environment and no point rewards were administered. On the test day, we observe that participants displayed a significant CPP for the room paired with points, as evidenced by significant differences in rating each of the rooms in terms of enjoyment. In Experiment 2, 77 undergraduates were tested using a biased conditioning approach in which an initial test session was conducted to obtain the participant's preferred room bias, and then the least-preferred room was designated as the points reward room for each participant. Using this biased conditioning approach, participants spent a significantly greater amount of time in the points-paired room. In this case, participants showed preferences based on explicit and implicit measures. These results suggest new approaches to examine the role of secondary reinforcers in nontraditional addictions such as internet, gaming, and gambling dependencies.


Assuntos
Condicionamento Psicológico , Recompensa , Percepção Espacial , Feminino , Humanos , Masculino , Testes Psicológicos , Comportamento Espacial , Tempo , Interface Usuário-Computador , Adulto Jovem
14.
Behav Brain Res ; 291: 277-282, 2015 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-26003943

RESUMO

The aim of this experiment was to examine the extent to which eating disorder risk affects the strength of food-reward conditioning. Eighty food-restricted undergraduates were placed into a VR environment consisting of two visually distinct rooms. Participants underwent multiple pairing sessions in which they were confined into one of the two rooms and explored a VR environment. Room A was paired with real-life M&Ms for three sessions, and Room B was paired with no food for three sessions. After a short delay, a test session was administered, and participants were given free access to the entire VR environment for 5 min. Participants also completed the Eating Attitudes Test (EAT-26; [11]), which is a standard screening tool of eating disorder risk. Participants displayed a significant conditioned place preference for the VR room previously paired with food, and they displayed a significant explicit preference for the M&M-paired room in a forced-choice test. There was a significant positive correlation between place preference strength and scores on the dieting subscale of the EAT-26. Additionally, ratings of the no-food room were significantly lower as dieting scores increased. This suggests that components of eating disorder risk can influence basic conditioning strength to places associated with food reward. For both males and females, additional correlations between eating disorder risk subscales and conditioning variables are discussed, and implications for future research are proposed in hopes of understanding how conditioning paradigms can provide insight into treating and preventing eating disorders.


Assuntos
Restrição Calórica/psicologia , Condicionamento Clássico , Transtornos da Alimentação e da Ingestão de Alimentos/psicologia , Alimentos , Recompensa , Cacau , Comportamento de Escolha , Transtornos da Alimentação e da Ingestão de Alimentos/diagnóstico , Transtornos da Alimentação e da Ingestão de Alimentos/epidemiologia , Feminino , Humanos , Masculino , Escalas de Graduação Psiquiátrica , Testes Psicológicos , Risco , Comportamento Espacial , Interface Usuário-Computador , Adulto Jovem
15.
Behav Brain Res ; 267: 173-7, 2014 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-24657735

RESUMO

To extend a standard paradigm of conditioning in nonhumans to humans, we created a virtual reality (VR) conditioned place preference task, with real-life food rewards. Undergraduates were placed into a VR environment consisting of 2 visually distinct rooms. On Day 1, participants underwent 6 pairing sessions in which they were confined into one of the two rooms and explored the VR environment. Room A was paired with real-life M&Ms for 3 sessions, and Room B was paired with no food for 3 sessions. Day 2 was the test day, administered the next day, and participants were given free access to the entire VR environment for 5min. In experiment 1, participants were food restricted, and we observed that on the test day, participants display a significant conditioned place preference for the VR room previously paired with food (p<0.001). Additionally, they display a significant explicit preference for the M&M-paired room in a forced-choice of "Which room do you like best?". In experiment 2, when participants were not food restricted, there was no evidence of a place preference, either implicitly (e.g. dwell time) or explicitly. Hence, we show that we can reliably establish a place preference in humans, but that the preference is contingent on the participants' hunger state. Future research will examine the extent to which these preferences can be blocked or extinguished as well as whether these preferences are evident using other reinforcers.


Assuntos
Condicionamento Psicológico , Testes Psicológicos , Percepção Espacial , Interface Usuário-Computador , Cacau , Comportamento de Escolha , Feminino , Privação de Alimentos , Humanos , Fome , Masculino , Recompensa , Comportamento Espacial , Análise e Desempenho de Tarefas , Adulto Jovem
16.
Behav Sci (Basel) ; 3(2)2013 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-24244873

RESUMO

Abnormal hippocampal function likely contributes to relational learning deficits observed in schizophrenia. It is unknown whether these deficits can be attenuated with a training intervention. The purpose of this project was to determine if training could facilitate relational learning of the transverse patterning task in schizophrenia. Healthy and schizophrenia subjects completed a version of transverse patterning that incorporated training. The majority of subjects with schizophrenia successfully learned transverse patterning when provided with training. A subgroup (approximately 25%) of schizophrenia subjects showed no tendency to learn with training. These results were replicated in a second study with a separate cohort and different stimuli. This study illustrates that relational learning of the transverse patterning can be facilitated in schizophrenia with training.

17.
Schizophr Res ; 135(1-3): 84-9, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22154760

RESUMO

Learning and memory impairments are present in schizophrenia (SZ) throughout the illness course and predict psychosocial function. Abnormalities in prefrontal and hippocampal function are thought to contribute to SZ deficits. The radial arm maze (RAM) is a test of spatial learning and memory in rodents that relies on intact prefrontal and hippocampal function. The goal of the present study was to investigate spatial learning in SZ using a virtual RAM. Thirty-three subjects with SZ and thirty-nine healthy controls (HC) performed ten trials of a virtual RAM task. Subjects attempted to learn to retrieve four rewards each located in separate arms. As expected, subjects with SZ used more time and traveled more distance to retrieve rewards, made more reference (RM) and working memory (WM) errors, and retrieved fewer rewards than HC. It is important to note that the SZ group did learn but did not reach the level of HC. Whereas RM errors decreased across trials in the SZ group, WM errors did not. There were no significant relationships between psychiatric symptom severity and maze performance. To our knowledge, use of a virtual 8-arm radial maze task in SZ to assess spatial learning is novel. Impaired virtual RAM performance in SZ is consistent with studies that examined RAM performance in animal models of SZ. Results provide further support for compromised prefrontal and hippocampal function underlying WM and RM deficits in SZ. The virtual RAM task could help bridge preclinical and clinical research for testing novel drug treatments of SZ.


Assuntos
Aprendizagem em Labirinto/fisiologia , Transtornos da Memória/diagnóstico , Transtornos da Memória/etiologia , Esquizofrenia/complicações , Percepção Espacial/fisiologia , Interface Usuário-Computador , Estimulação Acústica , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Escalas de Graduação Psiquiátrica , Fatores de Tempo
18.
Alcohol Clin Exp Res ; 34(3): 479-87, 2010 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-20028354

RESUMO

BACKGROUND: Driving while under the influence of alcohol is a major public health problem whose neural basis is not well understood. In a recently published functional magnetic resonance imaging (fMRI) study (Meda et al., 2009), our group identified 5, independent critical driving-associated brain circuits whose inter-regional connectivity was disrupted by alcohol intoxication. However, the functional connectivity between these circuits has not yet been explored in order to determine how these networks communicate with each other during sober and alcohol-intoxicated states. METHODS: In the current study, we explored such differences in connections between the above brain circuits and driving behavior, under the influence of alcohol versus placebo. Forty social drinkers who drove regularly underwent fMRI scans during virtual reality driving simulations following 2 alcohol doses, placebo and an individualized dose producing blood alcohol concentrations (BACs) of 0.10%. RESULTS: At the active dose, we found specific disruptions of functional network connectivity between the frontal-temporal-basal ganglia and the cerebellar circuits. The temporal connectivity between these 2 circuits was found to be less correlated (p < 0.05) when driving under the influence of alcohol. This disconnection was also associated with an abnormal driving behavior (unstable motor vehicle steering). CONCLUSIONS: Connections between frontal-temporal-basal ganglia and cerebellum have recently been explored; these may be responsible in part for maintaining normal motor behavior by integrating their overlapping motor control functions. These connections appear to be disrupted by alcohol intoxication, in turn associated with an explicit type of impaired driving behavior.


Assuntos
Intoxicação Alcoólica/fisiopatologia , Condução de Veículo , Encéfalo/fisiopatologia , Rede Nervosa/fisiopatologia , Adulto , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Adulto Jovem
19.
Psychiatry Res ; 166(2-3): 158-65, 2009 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-19278735

RESUMO

Sex differences are pervasive in schizophrenia, ranging from differences in the age of onset and symptoms of the illness to structural brain differences. Yet, there has been very little research on the interaction of these differences with established cognitive sex differences that exist in healthy populations. We tested 25 patients with schizophrenia and 17 healthy controls on a two-dimensional task of object location memory. It has been previously shown that healthy females outperform healthy males on this task, a result that was upheld in this experiment. However, the female advantage is completely absent in patients with schizophrenia. This finding has important implications for the interpretation of clinical and physiological sex differences present in schizophrenia.


Assuntos
Memória , Orientação , Reconhecimento Visual de Modelos , Reconhecimento Psicológico , Esquizofrenia , Percepção Espacial , Adulto , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Escalas de Graduação Psiquiátrica , Desempenho Psicomotor , Transtornos Psicóticos/diagnóstico , Transtornos Psicóticos/psicologia , Esquizofrenia/diagnóstico , Esquizofrenia/fisiopatologia , Fatores Sexuais
20.
Hum Brain Mapp ; 30(4): 1257-70, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18571794

RESUMO

Driving while intoxicated remains a major public health hazard. Driving is a complex task involving simultaneous recruitment of multiple cognitive functions. The investigators studied the neural substrates of driving and their response to different blood alcohol concentrations (BACs), using functional magnetic resonance imaging (fMRI) and a virtual reality driving simulator. We used independent component analysis (ICA) to isolate spatially independent and temporally correlated driving-related brain circuits in 40 healthy, adult moderate social drinkers. Each subject received three individualized, separate single-blind doses of beverage alcohol to produce BACs of 0.05% (moderate), 0.10% (high), or 0% (placebo). 3 T fMRI scanning and continuous behavioral measurement occurred during simulated driving. Brain function was assessed and compared using both ICA and a conventional general linear model (GLM) analysis. ICA results replicated and significantly extended our previous 1.5T study (Calhoun et al. [2004a]: Neuropsychopharmacology 29:2097-2017). GLM analysis revealed significant dose-related functional differences, complementing ICA data. Driving behaviors including opposite white line crossings and mean speed independently demonstrated significant dose-dependent changes. Behavior-based factors also predicted a frontal-basal-temporal circuit to be functionally impaired with alcohol dosage across baseline scaled, good versus poorly performing drivers. We report neural correlates of driving behavior and found dose-related spatio-temporal disruptions in critical driving-associated regions including the superior, middle and orbito frontal gyri, anterior cingulate, primary/supplementary motor areas, basal ganglia, and cerebellum. Overall, results suggest that alcohol (especially at high doses) causes significant impairment of both driving behavior and brain functionality related to motor planning and control, goal directedness, error monitoring, and memory.


Assuntos
Condução de Veículo , Encéfalo/efeitos dos fármacos , Depressores do Sistema Nervoso Central/farmacologia , Simulação por Computador , Etanol/farmacologia , Rede Nervosa/efeitos dos fármacos , Adulto , Análise de Variância , Encéfalo/irrigação sanguínea , Mapeamento Encefálico , Relação Dose-Resposta a Droga , Feminino , Lateralidade Funcional , Humanos , Processamento de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos , Masculino , Oxigênio/sangue , Análise de Componente Principal , Desempenho Psicomotor/efeitos dos fármacos , Método Simples-Cego , Fatores de Tempo , Interface Usuário-Computador , Adulto Jovem
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