Neural evidence of switch processes during semantic and phonetic foraging in human memory.

Humans may retrieve words from memory by exploring and exploiting in "semantic space" similar to how nonhuman animals forage for resources in physical space. This has been studied using the verbal fluency test (VFT), in which participants generate words belonging to a semantic or phonetic category in a limited time. People produce bursts of related items during VFT, referred to as "clustering" and "switching." The strategic foraging model posits that cognitive search behavior is guided by a monitoring process which detects relevant declines in performance and then triggers the searcher to seek a new patch or cluster in memory after the current patch has been depleted. An alternative body of research proposes that this behavior can be explained by an undirected rather than strategic search process, such as random walks with or without random jumps to new parts of semantic space. This study contributes to this theoretical debate by testing for neural evidence of strategically timed switches during memory search. Thirty participants performed category and letter VFT during functional MRI. Responses were classified as cluster or switch events based on computational metrics of similarity and participant evaluations. Results showed greater hippocampal and posterior cerebellar activation during switching than clustering, even while controlling for interresponse times and linguistic distance. Furthermore, these regions exhibited ramping activity which increased during within-patch search leading up to switches. Findings support the strategic foraging model, clarifying how neural switch processes may guide memory search in a manner akin to foraging in patchy spatial environments.

Reward anticipation-related neural activation following cued reinforcement in adults with psychotic psychopathology and biological relatives.

BACKGROUND: Schizophrenia is associated with hypoactivation of reward sensitive brain areas during reward anticipation. However, it is unclear whether these neural functions are similarly impaired in other disorders with psychotic symptomatology or individuals with genetic liability for psychosis. If abnormalities in reward sensitive brain areas are shared across individuals with psychotic psychopathology and people with heightened genetic liability for psychosis, there may be a common neural basis for symptoms of diminished pleasure and motivation. METHODS: We compared performance and neural activity in 123 people with a history of psychosis (PwP), 81 of their first-degree biological relatives, and 49 controls during a modified Monetary Incentive Delay task during fMRI. RESULTS: PwP exhibited hypoactivation of the striatum and anterior insula (AI) during cueing of potential future rewards with each diagnostic group showing hypoactivations during reward anticipation compared to controls. Despite normative task performance, relatives demonstrated caudate activation intermediate between controls and PwP, nucleus accumbens activation more similar to PwP than controls, but putamen activation on par with controls. Across diagnostic groups of PwP there was less functional connectivity between bilateral caudate and several regions of the salience network (medial frontal gyrus, anterior cingulate, AI) during reward anticipation. CONCLUSIONS: Findings implicate less activation and connectivity in reward processing brain regions across a spectrum of disorders involving psychotic psychopathology. Specifically, aberrations in striatal and insular activity during reward anticipation seen in schizophrenia are partially shared with other forms of psychotic psychopathology and associated with genetic liability for psychosis.

Neural correlates of visual attention during risky decision evidence integration.

Value-based decision-making is presumed to involve a dynamic integration process that supports assessing the potential outcomes of different choice options. Decision frameworks assume the value of a decision rests on both the desirability and risk surrounding an outcome. Previous work has highlighted neural representations of risk in the human brain, and their relation to decision choice. Key neural regions including the insula and anterior cingulate cortex (ACC) have been implicated in encoding the effects of risk on decision outcomes, including approach and avoidance. Yet, it remains unknown whether these regions are involved in the dynamic integration processes that precede and drive choice, and their relationship with ongoing attention. Here, we used concurrent fMRI and eye-tracking to discern neural activation related to visual attention preceding choice between sure-thing (i.e. safe) and risky gamble options. We found activation in both dorsal ACC (dACC) and posterior insula (PI) scaled in opposite directions with the difference in attention to risky rewards relative to risky losses. PI activation also differentiated foveations on both risky options (rewards and losses) relative to a sure-thing option. These findings point to ACC involvement in ongoing evaluation of risky but higher value options. The role of PI in risky outcomes points to a more general evaluative role in the decision-making that compares both safe and risky outcomes, irrespective of potential for gains or losses.

Associations between hypomania proneness and attentional bias to happy, but not angry or fearful, faces in emerging adults.

Mania, the core feature of bipolar disorder, is associated with heightened and positive emotion responding. Yet, little is known about the underlying cognitive processes that may contribute to heightened positive emotionality observed. Additionally, while previous research has investigated positive emotion biases in non-clinical samples, few if any, account for subthreshold clinical symptoms or traits, which have reliably assessed psychopathological risk. The present study compared continuous scores on a widely used self-report measure of hypomania proneness (HPS-48) with a dot-probe task to investigate attentional biases for happy, angry, fearful, and neutral faces among 66 college student participants. Results suggested that hypomania proneness was positively associated with attentional bias towards happy, but not angry or fearful faces. Results remained robust when controlling for positive affect and did not appear to be affected by negative affect or current symptoms of depression, anxiety, and stress. Findings provide insight into potential behavioural markers that co-occur with heightened positive emotional responding and hypomania in emerging adults.

Modeling Decision-Making in Schizophrenia: Associations Between Computationally Derived Risk Propensity and Self-Reported Risk Perception.

BACKGROUND AND HYPOTHESIS: Schizophrenia is associated with a decreased pursuit of risky rewards during uncertain-risk decision-making. However, putative mechanisms subserving this disadvantageous risky reward pursuit, such as contributions of cognition and relevant traits, remain poorly understood. STUDY DESIGN: Participants (30 schizophrenia/schizoaffective disorder [SZ]; 30 comparison participants [CP]) completed the Balloon Analogue Risk Task (BART). Computational modeling captured subprocesses of uncertain-risk decision-making: Risk Propensity, Prior Belief of Success, Learning Rate, and Behavioral Consistency. IQ, self-reported risk-specific processes (ie, Perceived Risks and Expected Benefit of Risks), and non-risk-specific traits (ie, defeatist beliefs; hedonic tone) were examined for relationships with Risk Propensity to determine what contributed to differences in risky reward pursuit. STUDY RESULTS: On the BART, the SZ group exhibited lower Risk Propensity, higher Prior Beliefs of Success, and comparable Learning Rates. Furthermore, Risk Propensity was positively associated with IQ across groups. Linear models predicting Risk Propensity revealed 2 interactions: 1 between group and Perceived Risk, and 1 between IQ and Perceived Risk. Specifically, in both the SZ group and individuals with below median IQ, lower Perceived Risks was related to lower Risk Propensity. Thus, lower perception of financial risks was associated with a less advantageous pursuit of uncertain-risk rewards. CONCLUSIONS: Findings suggest consistently decreased risk-taking on the BART in SZ may reflect risk imperception, the failure to accurately perceive and leverage relevant information to guide the advantageous pursuit of risky rewards. Additionally, our results highlight the importance of cognition in uncertain-risk decision-making.

Insular and Striatal Correlates of Uncertain Risky Reward Pursuit in Schizophrenia.

BACKGROUND AND HYPOTHESIS: Risk-taking in specific contexts can be beneficial, leading to rewarding outcomes. Schizophrenia is associated with disadvantageous decision-making, as subjects pursue uncertain risky rewards less than controls. However, it is unclear whether this behavior is associated with more risk sensitivity or less reward incentivization. Matching on demographics and intelligence quotient (IQ), we determined whether risk-taking was more associated with brain activation in regions affiliated with risk evaluation or reward processing. STUDY DESIGN: Subjects (30 schizophrenia/schizoaffective disorder, 30 controls) completed a modified, fMRI Balloon Analogue Risk Task. Brain activation was modeled during decisions to pursue risky rewards and parametrically modeled according to risk level. STUDY RESULTS: The schizophrenia group exhibited less risky-reward pursuit despite previous adverse outcomes (Average Explosions; F(1,59) = 4.06, P = .048) but the comparable point at which risk-taking was volitionally discontinued (Adjusted Pumps; F(1,59) = 2.65, P = .11). Less activation was found in schizophrenia via whole brain and region of interest (ROI) analyses in the right (F(1,59) = 14.91, P < 0.001) and left (F(1,59) = 16.34, P < 0.001) nucleus accumbens (NAcc) during decisions to pursue rewards relative to riskiness. Risk-taking correlated with IQ in schizophrenia, but not controls. Path analyses of average ROI activation revealed less statistically determined influence of anterior insula upon dorsal anterior cingulate bilaterally (left: χ2 = 12.73, P < .001; right: χ2 = 9.54, P = .002) during risky reward pursuit in schizophrenia. CONCLUSIONS: NAcc activation in schizophrenia varied less according to the relative riskiness of uncertain rewards compared to controls, suggesting aberrations in reward processing. The lack of activation differences in other regions suggests similar risk evaluation. Less insular influence on the anterior cingulate may relate to attenuated salience attribution or inability for risk-related brain region collaboration to sufficiently perceive situational risk.

The cannabidiol and marijuana research expansion act: Promotion of scientific knowledge to prevent a national health crisis.

While the use of medical and recreational cannabis is rapidly expanding under state jurisdiction, the convolution of federal regulations is obstructing research progress to the detriment of healthcare equity and the protection of vulnerable populations, such as the underaged. U.S. Senate bill S.253 is designed to accelerate the development of trusted preclinical and clinical principles based on scientific data to guide physicians in their daily practice, inform lawmakers, and thereby protect public health. This goes together with a reinforcement of the legal protection that practitioners have acquired over years of litigation with the federal government when working with their patients. S.253 supports open communication between physicians and their patients when discussing cannabis as a treatment option. The bill passed the U.S. Senate on March 24, 2022. Funding: This work was supported by intramural funding (NYIT College of Osteopathic Medicine) to the corresponding author, Dr. Joerg R. Leheste.

A review of risky decision-making in psychosis-spectrum disorders.

The investigation of risky decision-making has a prominent place in clinical science, with sundry behavioral tasks aimed at empirically quantifying the psychological construct of risk-taking. However, use of differing behavioral tasks has resulted in lack of agreement on risky decision-making within psychosis-spectrum disorders, as findings fail to converge upon the typical, binary conceptualization of increased risk-seeking or risk-aversion. The current review synthesizes the behavioral, risky decision-making literature to elucidate how specific task parameters may contribute to differences in task performance, and their associations with psychosis symptomatology and cognitive functioning. A paring of the literature suggests that: 1) Explicit risk-taking may be characterized by risk imperception, evidenced by less discrimination between choices of varying degrees of risk, potentially secondary to cognitive deficits. 2) Ambiguous risk-taking findings are inconclusive with few published studies. 3) Uncertain risk-taking findings, consistently interpreted as more risk-averse, have not parsed risk attitudes from confounding processes that may impact decision-making (e.g. risk imperception, reward processing, motivation). Thus, overgeneralized interpretations of task-specific risk-seeking/aversion should be curtailed, as they may fail to appropriately characterize decision-making phenomena. Future research in psychosis-spectrum disorders would benefit from empirically isolating contributions of specific processes during risky decision-making, including the newly hypothesized risk imperception.

Early-Onset Parkinson's Disease With Multiple Positive Intraoperative Spinal Tissue Cultures for Cutibacterium acnes.

An estimated 95-97% of Parkinson's disease (PD) cases are idiopathic, emphasizing the absence of a clear etiologic linkage for this debilitating, neurodegenerative, and progressive motor disease. Increasing evidence suggests a peripheral disease origin and the gradual transition of a pathological process along the gut-brain axis and olfactory routes into the brain. This disease pattern is reminiscent of an infectious process and suggests the presence of one or multiple infectious agents, such as bacteria, viruses, fungi, or prion-like proteins. This unusual paradigm, known as Braak's hypothesis, was first described by the scientist who developed the staging standard for cellular PD pathology and. Here, we describe a case where the small, anaerobic, Gram-positive Cutibacterium acnes was recurrently isolated from intraoperative spinal tissues in a patient with early-onset PD. C. acnes is also the bacterium that we previously isolated from cadaveric PD brain tissue. Both observations are consistent with Braak's hypothesis underscoring the importance of homeostasis and maintained immune-competence for healthy aging of the body and mind.

Cerebellar Activation Deficits in Schizophrenia During an Eyeblink Conditioning Task.

The cognitive dysmetria theory of psychotic disorders posits that cerebellar circuit abnormalities give rise to difficulties coordinating motor and cognitive functions. However, brain activation during cerebellar-mediated tasks is understudied in schizophrenia. Accordingly, this study examined whether individuals with schizophrenia have diminished neural activation compared to controls in key regions of the delay eyeblink conditioning (dEBC) cerebellar circuit (eg, lobule VI) and cerebellar regions associated with cognition (eg, Crus I). Participants with schizophrenia-spectrum disorders (n = 31) and healthy controls (n = 43) underwent dEBC during functional magnetic resonance imaging (fMRI). Images were normalized using the Spatially Unbiased Infratentorial Template (SUIT) of the cerebellum and brainstem. Activation contrasts of interest were "early" and "late" stages of paired tone and air puff trials minus unpaired trials. Preliminary whole brain analyses were conducted, followed by cerebellar-specific SUIT and region of interest (ROI) analyses of lobule VI and Crus I. Correlation analyses were conducted between cerebellar activation, neuropsychological test scores, and psychotic symptom scores. In controls, the largest clusters of cerebellar activation peaked in lobule VI during early dEBC and Crus I during late dEBC. The schizophrenia group showed robust cortical activation to unpaired trials but no significant conditioning-related cerebellar activation. Crus I ROI activation during late dEBC was greater in the control than schizophrenia group. Greater Crus I activation correlated with higher working memory scores in the full sample and lower positive psychotic symptom severity in schizophrenia. Findings indicate functional cerebellar abnormalities in schizophrenia which relate to psychotic symptoms, lending direct support to the cognitive dysmetria framework.

Understanding and Taking Stock of Positive Emotion Disturbance.

The prevailing view on positive emotions is that they correlate with and confer psychological health benefits for the individual, including improved social, physical and cognitive functioning. Yet an emerging wave of scientific work suggests that positive emotions are also related to a range of suboptimal psychological health outcomes, especially when the intensity, duration, or context do not optimize the individual's goals or meet current environmental demands. This paper provides an overview of the 'other side' of positive emotion, by describing and reviewing evidence supporting the emerging field of Positive Emotion Disturbance (PED). We review relevant emotion processes and key themes of PED and apply this framework to example emotional disorders, and discuss implications for psychological change and future research agendas.

Correction to: Psychometric evaluation of the Pinocchio Illusion Questionnaire.

The authors would like to correct the following.

Psychometric evaluation of the Pinocchio Illusion Questionnaire.

Perceived nose elongation resulting from vibratory stimulation to the bicep brachii tendon in the absence of visual input while the finger is touching the nose, known as the Pinocchio Illusion (PI), is used to investigate how afferent signals can contribute to aberrant top-down perception of body representation. The Pinocchio Illusion Questionnaire (PIQ) was developed to empirically quantify PI perception, allowing for external validation of the PI with psychologically relevant phenomenon. The current study (N = 60) examined the PIQ's test-retest reliability, internal consistency, factor structure, and correlations with self-reported interoceptive awareness and schizotypal traits. The PIQ demonstrated strong test-retest reliability and internal validity; however, a Principal Component Analysis did not yield a latent variable structure that distinguished PI-specific perceptual aberrations from unrelated or contradictory perceptual experiences. Additionally, decreased reports of PI-specific perceptual aberrations during two elicitations of the PI on the PIQ's open-ended free-response section (percent of sample endorsement = 5% (first elicitation); 8.3% (second elicitation)) compared to its 11-item section (endorsement of PI-specific items ranging 30-53.33% (first)]; 31.67-46.67% (second)) suggest that these responses may be heavily influenced by demand characteristics rather than accurately capturing PI perception. Therefore, further psychometric development of the PIQ and standardization of procedures to elicit the illusion are recommended.

Buckling of a linear chain of hard spheres in a harmonic confining potential: Numerical and analytical results for low and high compression.

We extend a previous analysis of the buckling properties of a linear chain of hard spheres between hard walls under transverse harmonic confinement. Two regimes are distinguished-low compression, for which the entire chain buckles, and higher compression, for which there is localized buckling. With further increase of compression, second-neighbor contacts occur; beyond this compression the structure is no longer planar, and is not treated here. A continuous model is developed which is amenable to analytical solution in the low compression regime. This is helpful in understanding the scaling properties of both finite and infinite chains.

Impaired Effective Connectivity During a Cerebellar-Mediated Sensorimotor Synchronization Task in Schizophrenia.

Prominent conceptual models characterize schizophrenia as a dysconnectivity syndrome, with recent research focusing on the contributions of the cerebellum in this framework. The present study examined the role of the cerebellum and its effective connectivity to the cerebrum during sensorimotor synchronization in schizophrenia. Specifically, the role of the cerebellum in temporally coordinating cerebral motor activity was examined through path analysis. Thirty-one individuals diagnosed with schizophrenia and 40 healthy controls completed a finger-tapping fMRI task including tone-paced synchronization and self-paced continuation tapping at a 500 ms intertap interval (ITI). Behavioral data revealed shorter and more variable ITIs during self-paced continuation, greater clock (vs motor) variance, and greater force of tapping in the schizophrenia group. In a whole-brain analysis, groups showed robust activation of the cerebellum during self-paced continuation but not during tone-paced synchronization. However, effective connectivity analysis revealed decreased connectivity in individuals with schizophrenia between the cerebellum and primary motor cortex but increased connectivity between cerebellum and thalamus during self-paced continuation compared with healthy controls. These findings in schizophrenia indicate diminished temporal coordination of cerebral motor activity by cerebellum during the continuation tapping portion of sensorimotor synchronization. Taken together with the behavioral finding of greater temporal variability in schizophrenia, these effective connectivity results are consistent with structural and temporal models of dysconnectivity in the disorder.

Discriminating Formal Representations of Risk in Anterior Cingulate Cortex and Inferior Frontal Gyrus.

Considerable debate persists around the definition of risk. Depending on the area of study, the concept of risk may be defined as the variance of the possible outcomes, the probability of a loss, or a combination of the loss probability and its maximum possible loss. Mounting evidence suggests the anterior cingulate cortex (ACC), including the surrounding medial prefrontal cortex (mPFC), and the anterior insula/inferior frontal gyrus (IFG) are key neural regions that represent perceived risks. Yet it remains unclear which of these formalisms best accounts for the pattern of activation in brain regions representing risk, and it is also difficult to disentangle risk from value, as both contribute to perceived utility. To adjudicate among the possible definitions, we used fMRI with a novel gambling task that orthogonalized the variance, loss probability, and maximum possible loss among the risky options, while maintaining a constant expected value across all monetary gambles to isolate the impact of risk rather than value. Here we show that when expected value is controlled for ACC and IFG activation reflect variance, but neither loss probability nor maximum possible loss. Across subjects, variance-related activation within the ACC correlates indirectly with risk aversion. Our results highlight the variance of the prospective outcomes as a formal representation of risk that is reflected both in brain activity and behavior, thus suggestive of a stronger link among formal economic theories of financial risk, naturalistic risk taking, and neural representations of risk.

Lack of emotional gaze preferences using eye-tracking in remitted bipolar I disorder.

BACKGROUND: Bipolar disorder is associated with heightened and persistent positive emotion (Gruber in Curr Dir Psychol Sci 20:217-221, 2011; Johnson in Clin Psychol Rev 25:241-262, 2005). Yet little is known about information processing biases that may influence these patterns of emotion responding. METHODS: The current study adopted eye-tracking methodology as a continuous measure of sustained overt attention to monitor gaze preferences during passive viewing of positive, negative, and neutral standardized photo stimuli among remitted bipolar adults and healthy controls. Percentage fixation durations were recorded for predetermined areas of interest across the entire image presentation, and exploratory analyses were conducted to examine early versus late temporal phases of image processing. RESULTS: Results suggest that the bipolar and healthy control groups did not differ in patterns of attention bias. CONCLUSIONS: Findings provide insight into apparently intact attention processing despite disrupted emotional responding in bipolar disorder.

Weak genetic structure indicates strong dispersal limits: a tale of two coral reef fish.

The extent of dispersal by pelagic larvae in marine environments, including coral reefs, is central for understanding local population dynamics and designing sustainable marine reserves. We present here the first example of a clear stepping-stone genetic structure throughout the Caribbean basin for a common coral reef species, the French grunt (Haemulon flavolineatum). Analysis of microsatellite DNA markers indicated that French grunt population structure may be characterized by overlapping populations throughout the Caribbean, influenced by independent population dynamics but with no fixed geographical boundaries. In addition, different spatial genetic patterns were found in different oceanographic regions. A second species, the bluehead wrasse (Thalassoma bifasciatum), has a much longer pelagic larval duration than French grunts and showed no explicit spatial pattern of genetic variation. This finding is concordant with the hypothesis of a positive relationship between larval dispersal and duration in the plankton. While the magnitude of the genetic signal of population structure in French grunts was very low (F(ST) approximately 0.003), the pattern of isolation-by-distance throughout the Caribbean indicated considerable population structure with important ecological and conservation significance.

Harm, intent, and the nature of aggressive behavior: measuring naturally occurring aggression in barroom settings.

The research goals were to use the constructs of harm and intent to quantify the severity of aggression in the real-world setting of the bar/club, to describe the range of aggressive behaviors and their relationship to harm and intent, and to examine gender differences in the form and severity of aggression. Systematic observations were conducted by trained observers on 1,334 nights in 118 bars/clubs. Observers documented a range of aggressive acts by 1,754 patrons in 1,052 incidents, with many forms of aggression occurring at more than one harm and intent level. Women used different forms of aggression, inflicted less harm, and were more likely to have defensive intent compared with men. Implications of the findings for research and measurement of aggression and applications to preventing aggression and violence are discussed.