"It helps and it doesn't help": maternal perspectives on how the use of smartphones and tablet computers influences parent-infant attachment.

As families increase their use of mobile touch screen devices (smartphones and tablet computers), there is potential for this use to influence parent-child interactions required to form a secure attachment during infancy, and thus future child developmental outcomes. Thirty families of infants (aged 9-15 months) were interviewed to explore how parents and infants use these devices, and how device use influenced parents' thoughts, feelings and behaviours towards their infant and other family interactions. Two-thirds of infants were routinely involved in family video calls and one-third used devices for other purposes. Parent and/or child device use served to both enhance connection and increase distraction between parents and infants and between other family members. Mechanisms for these influences are discussed. The findings highlight a new opportunity for how hardware and software should be designed and used to maximise benefits and reduce detriments of device use to optimise parent-infant attachment and child development.Practitioner Summary: Many families with infants regularly use smartphones and tablet computers. This qualitative study found that how devices were used either enhanced or disrupted feelings of parent-infant attachment. Practitioners should be aware of the potential beneficial and detrimental impacts of device use among families given implications for attachment and future child development.

Self Capacitance Mismatch Calibration Technique for Fully-Differential Touch Screen Panel Self Capacitance Sensing System.

This paper presents a fully-differential touch screen panel (TSP) self-capacitance sensing (SCS) system with a self-capacitance mismatch calibration technique. Due to the self-capacitance mismatch of TSP, the analog front-end (AFE) of the receiver (RX) circuit suffers from dynamic range degradation and gain limitations, which lead to the signal-to-noise ratio (SNR) loss for the TSP SCS system. The proposed calibration introduces the difference in input resistance and the driving amplifier's strength between the fully-differential input. Thus, the mismatch effect is efficiently relieved in terms of area and power consumption. The proposed calibration restores the SNR by 19.54 dB even under the worst self-capacitance mismatch case.

Effect of icon size, icon position and sex on clicking motion when operating smartphones with single hand.

Nowadays, increasingly more situations exist where smartphones are operated with one hand, requiring an in-depth understanding of human-computer interaction in single-hand scenarios. 104 volunteers (57 men, 47 women) participated in this study. We aimed to explore thumb movements with the right and left hand on smartphone touchscreens at different icon sizes (50, 80, 110 and 140 rpx) in different operation areas (a 4*7 icon matrix). The results partially conformed to Fitts' Law. The movement time (MT) significantly increased as the icon size decreased, but this effect was not found over 110 rpx. The MT increased with distance in the vertical direction, but icons with the same horizontal distance had different MTs, indicating that one-handed operation restricted the click on the same side. Additionally, subjects rated 140 rpx better than other sizes, and men clicked faster than women. Suggestions regarding one-handed interface design for different hands of different sexes are provided.Practitioner summary: This study investigated how icon size, position and sex influenced one-thumb click usability on touch-screen mobile phones with different hands of different sexes. The results indicate single-hand operation partially conformed to Fitts' Law. We suggested the most economical and comfortable size and the fast operation area in one-handed interface design.Abbreviations: MT: movement time; ID: index of difficulty; RPX: responsive pixel; NASA-TLX: task load index of National Aeronautics and Space Administration; ANOVA: analysis of variance.

Influence of size and location of buttons on the usability of interface on large touch screens.

This study examined how large touchscreen buttons affect user task completion time, error rate, and subjective satisfaction (ease of pointing and clicking on targets). In this experiment, 31 participants completed button click tasks of square targets placed at 30 (5 × 6) different locations, with seven button sizes (10 mm, 30 mm, 50 mm, 70 mm, 90 mm, 110 mm, and 130 mm). Repeated measures ANOVAs showed that on a 65'' large touch screen (W 1428 × H 803 mm), 70 mm buttons achieved essentially the best performance in completion time, 50 mm in error rates, and 90 mm in subjective satisfaction, respectively. We also compare the differences in efficiency among different button areas and button sizes. The surrounding area and lower area require a bigger button size to achieve the best performance in terms of error rates and subjective satisfaction. The right area requires a bigger optimal button size than the left area considering error rates, while it is the opposite for subjective satisfaction.Practitioner summary: This study investigates how the size and location of buttons on the increasingly popular large touch screen affect user experience. The study reveals that 70, 50, 90 mm size buttons are recommended when speed, accuracy and satisfaction are priorities respectively. The interaction between button size and button area is significantly different. The surrounding area and lower area require a bigger button size to achieve the best performance in terms of error rate and subjective satisfaction. Considering error rates, the right area requires a bigger optimal button size than the left area, while it is opposite for subjective satisfaction. These findings could facilitate the optimal design of usable large touch screens.

A Low-Computing-Complexity Touch Signal Detection Method and Analog Front-End Circuits Based on Cross-Correlation Technology for Large-Size Touch Panel.

This paper proposes a low-computing-complexity touch signal detection method and analog front-end (AFE) circuits based on cross-correlation technology for large mutual capacitance touch screen panels (TSPs). To solve the traditional touch signal detection method problem of lots of invalid data being sampled and processed in a large-size TSP, the proposed method only samples and processes the signals around the touch points rather than full-screen data to decrease the computing complexity and analog-digital convertor (ADC) acquisition number. Compared with the traditional method, the proposed touch points search algorithm complexity decreases from MN to M + nN where M, N, and n are the number of RX channels, TX channels, and touch points, respectively. The maximum ADC acquisition number of the proposed method decreases from MN to 18n. Based on the proposed touch signal detection method, the AFE circuits are designed by a 0.11 µm process. The proposed dual cross-correlation AFE achieves detection of the weak touch signal submerged in the large display panel noise. The average channel area and power consumption are decreased to 0.015 mm2 and 0.227 mW, respectively. The maximum frame rate is 384.6 Hz with 10 touch points. The proposed cross-correlation AFE achieves a high frame rate while reducing the die area and power consumption.

'There's good and bad': parent perspectives on the influence of mobile touch screen device use on prenatal attachment.

The potential for human-computer interaction to have a substantial impact on adults is well documented. However, its potential importance prior to birth has rarely been reported. Parental use of smartphones and tablet computers could influence the relationship between parent and baby during pregnancy (prenatal attachment) and thus child development. Twenty-seven families were interviewed to explore how parents used these devices during pregnancy, and how device use influenced parents' thoughts, feelings and behaviours towards their baby while in utero. All used devices for a variety of purposes, and all described good levels of prenatal attachment. Parents described both disrupted and enhanced connectedness as a result of device use, and increased parental stress. The findings highlight a new opportunity for how device design and use guidelines could support families to maximise benefits and reduce detriments of device use to optimise prenatal attachment, and thus future parent-child attachment and child development. Practitioner summary: Many parents regularly use smartphones and tablet computers while pregnant. This qualitative study found that how devices were used either enhanced or disrupted feelings of prenatal attachment. Practitioners should be aware of potential beneficial and detrimental impacts of device use during pregnancy given implications for future attachment and child development.

The use of digital touch screen technology to deliver reminiscence therapy among people with dementia in Jordanian care homes: a mixed-method feasibility study.

BACKGROUND: Using technology to deliver psychosocial interventions such as reminiscence therapy (RT) to people with dementia may improve their mental health. Yet, establishing the feasibility of digital interventions in low- to middle-income countries is still in the early stages. This study aimed to: (i) determine the feasibility of using digital touch screen technology to deliver RT among people with dementia living in Jordanian care homes; and (ii) compare study outcomes pre- and post-reminiscence sessions to investigate whether specific outcomes are sensitive to change and explore the acceptability and experiences of the intervention. METHODS: A pragmatic mixed-method study design was implemented. Sixty residents with dementia were recruited from two Jordanian care homes (Site 1: n = 35; Site 2: n = 10). A process evaluation was conducted alongside a single-group pre-post-intervention study. The intervention involved 10 supported RT sessions of up to 1 h each, delivered over 5 weeks. Feasibility was determined by assessing the rate of recruitment, adherence, retention, data completion, implementation fidelity, and adverse events. Qualitative semi-structured interview questions were used to explore experience and acceptability, and data were thematically analysed. RESULTS: Response rate was 100%; loss to follow up at post-intervention was 25%. Median session attendance for those who received the intervention was 80%. No serious adverse events were reported. A positive, statistically significant and clinically relevant difference was found in all outcome measures before and after reminiscence sessions. Qualitative findings suggest that digital RT intervention is generally well accepted by people with dementia who reported positive changes, including enhanced communication and cognitive abilities. CONCLUSION: Using digital touch screen technology to deliver RT is feasible and acceptable among people with dementia in Jordanian care homes. Digital RT intervention is a promising approach to improving mental health and communication for people living with dementia.

Field-testing an iCST touch-screen application with people with dementia and carers: a mixed method study.

OBJECTIVES: To test the individual Cognitive Stimulation Therapy (iCST) application with people with dementia and carers in order to modify and refine the application, and improve its usability. In an iterative development process, two different prototypes were used to elicit the subjects' views and preferences. This application may address the current need for more innovative approaches to support people with dementia and their carers. METHODS: An opportunistic sample of 13 people with dementia and 13 carers participated in four focus groups and ten semi-structured interviews to obtain feedback in key areas, including the layout and content of the application, and the experience of its use as a dyad. Data were audio-recorded, transcribed and analysed thematically. An additional 18 people with dementia and 16 carers completed a short usability and acceptability questionnaire regarding a subsequent version of the iCST application prototype. RESULTS: Most participants expressed enthusiasm about the iCST application, its usability, design, and content. Participants highlighted the importance of adaptability to individual preferences, indicating a need for a wider range of activities and flexibility in the use of the application. Furthermore, participants reported perceived benefits, including mental stimulation, quality time spent together, and enjoyment. The application was rated slightly better by carers than people with dementia in terms of usability and acceptability. CONCLUSIONS: This study gives insights from people with dementia and carers concerning the usability, feasibility, and perceived benefits of the iCST application. The feedback will be incorporated in an updated version of the iCST application for commercial release.

A PAPR Reduction Technique for Fast Touch Sensors Adopting a Multiple Frequency Driving Method on Large Display Panels.

The multiple frequency driving method (MFDM) capacitive touch system (CTS), which drives transmit (TX) electrodes in parallel, has been developed to improve the touch-sensitivity of large touch screens at high speed. However, when driving multiple TX electrodes at the same time, TX signals are merged through the touch panel, which results in increasing the peak-to-average power ratio (PAPR) of combined signals. Due to the high PAPR, the signal is distorted out of the power amplifier's linear range, causing a touch malfunction. The MFDM CTS can avoid this problem by reducing the drive voltage or partially driving the TX electrodes in parallel. However, these methods cause a significant performance drop with respect to signal-to-noise ratio (SNR) in the MFDM systems. This paper proposes a stack method which reduces PAPR effectively without the performance degradation of MFDM and achieves real-time touch sensitivity in large display panels. The proposed method allocates a suitable phase for each TX electrode to reduce the peak power of combined signals. Instead of investigating all of the phases for the total number of TX electrodes, the optimal phase is estimated from the highest frequency to the lowest one and fixed one by one, which can reduce the required time to find a suitable phase considerably. As a result, it enables high-speed sensing of multi-touch on a large touch screen and effectively reduces PAPR to secure high signal-to-noise-ratio (SNR). Through experiments, it was verified that the proposed method in this paper has an SNR of 39.36 dB, achieving a gain of 19.35 and 5.98 dB compared to the existing touch system method and the algorithm used in the communication system, respectively.

The association of mobile touch screen device use with parent-child attachment: a systematic review.

Mobile touch screen devices (smartphones and tablet computers) have become an integral part of many parents' and children's lives, with this interaction linked to physical, mental and social outcomes. Despite the known importance of parent-child attachment, evidence on the association between device use and attachment was yet to be reviewed. Following protocol pre-registration, databases were searched, papers screened, and methodological quality assessed. Three papers met the inclusion criteria, and reported some negative associations between duration of parent/child smartphone use and attachment outcomes. A narrative synthesis on two groups of related papers found child time using any screen technology (including television viewing), and child 'problematic' internet, mobile phone, gaming and social media use, was negatively associated with attachment outcomes. Currently there is limited direct evidence on any association between time parents or children spend using these devices and parent-child attachment to support time guidelines for families and professionals working with families. Practitioner summary: Many parents and children regularly spend time using smartphones and tablet computers. This systematic review found limited evidence evaluating associations between child/adolescent or parent time using devices and parent-child attachment. Until quality evidence exists, practitioners should be alert to potential impacts of device use on family relationships and child outcomes.

Enhancing Security on Touch-Screen Sensors with Augmented Handwritten Signatures.

We aim at enhancing personal identity security on mobile touch-screen sensors by augmenting handwritten signatures with specific additional information at the enrollment phase. Our former works on several available and private data sets acquired on different sensors demonstrated that there are different categories of signatures that emerge automatically with clustering techniques, based on an entropy-based data quality measure. The behavior of such categories is totally different when confronted to automatic verification systems in terms of vulnerability to attacks. In this paper, we propose a novel and original strategy to reinforce identity security by enhancing signature resistance to attacks, assessed per signature category, both in terms of data quality and verification performance. This strategy operates upstream from the verification system, at the sensor level, by enriching the information content of signatures with personal handwritten inputs of different types. We study this strategy on different signature types of 74 users, acquired in uncontrolled mobile conditions on a largely deployed mobile touch-screen sensor. Our analysis per writer category revealed that adding alphanumeric (date) and handwriting (place) information to the usual signature is the most powerful augmented signature type in terms of verification performance. The relative improvement for all user categories is of at least 93% compared to the usual signature.

Fully Differential Touch Screen Controller with Wide Input Dynamic Range for Thin Displays.

As today's smartphone displays become thinner, the coupling capacitance between the display electrodes and touch screen panel (TSP) electrodes is increasing significantly. The increased capacitance easily introduces time-varying display signals into the TSP, deteriorating the touch performance. In this research, we demonstrate that the maximum peak display noise in the time domain is approximately 30% of the maximum voltage difference of the display grayscale through analysis of the structure and operation of displays. Then, to mitigate display noise, we propose a circuit solution that uses a fully differential charge amplifier with an input dynamic range wider than the maximum peak of the display noise. A test chip was fabricated using a 0.35 µm CMOS process and achieved a signal-to-noise ratio of 41 dB for a 6-mm-diameter metal pillar touch when display pulses with 5-V swing were driven at 100 kHz.

Capacitive Heart-Rate Sensing on Touch Screen Panel with Laterally Interspaced Electrodes.

It is demonstrated that the heart-rate can be sensed capacitively on a touch screen panel (TSP) together with touch signals. The existing heart-rate sensing systems measure blood pulses by tracing the amount of light reflected from blood vessels during a number of cardiac cycles. This type of sensing system requires a considerable amount of power and space to be implemented in multi-functional mobile devices such as smart phones. It is found that the variation of the effective dielectric constant of finger stemming from the difference of systolic and diastolic blood flows can be measured with laterally interspaced top electrodes of TSP. The spacing between a pair of non-adjacent top electrodes turns out to be wide enough to distinguish heart-rate signals from noises. With the aid of fast Fourier transform, the heart-rate can be extracted reliably, which matches with the one obtained by actually counting heart beats on the wrist.

Genetic inactivation of hypoxia inducible factor 1-alpha (HIF-1α) in adult hippocampal progenitors impairs neurogenesis and pattern discrimination learning.

HIF-1α is a hypoxia-inducible protein that regulates many cellular processes, including neural stem cell maintenance. Previous work demonstrated constitutive stabilization of HIF-1α in neural stem cells (NSCs) of the adult mouse subventricular zone (SVZ) and hippocampal subgranular zone (SGZ). Genetic inactivation of NSC-encoded HIF-1α in the adult SVZ results in gradual loss of NSCs, but whether HIF-1α is required for the maintenance of SGZ hippocampal progenitors and adult hippocampal neurogenesis has not been determined. Here we tested the hypothesis that HIF-1α plays an essential role in the maintenance of adult hippocampal neurogenesis using Nestin-CreERT2/R26R-YFP/Hif1afl/fl triple transgenic mice, in which HIF-1α was genetically inactivated in nestin+ hippocampal progenitors and their downstream progeny following tamoxifen exposure. We found that disruption of HIF-1α gene expression resulted in a marked 50% reduction of adult-generated dentate granule cells (DGCs) that was highly correlated with impaired hippocampal function, as assessed using two behavioral assays of pattern discrimination. These behavioral tests included the A-B contextual fear-conditioning task and the trial-unique, delayed nonmatching-to-location (TUNL) touch-screen operant chamber task. Our findings identify HIF-1α as a novel regulator of adult hippocampal neurogenesis under non-pathological conditions, and underscore the importance of neurogenesis for pattern discrimination learning.

Increased Maternal Care Rescues Altered Reinstatement Responding Following Moderate Prenatal Alcohol Exposure.

BACKGROUND: Fetal alcohol spectrum disorders (FASD) commonly include deficits in learning, memory, and executive control that can have a severe negative impact on quality of life across the life span. It is still unclear how prenatal alcohol exposure (PAE) affects executive control processes, such as control over reward seeking, that lead to inappropriate behavior later in life. Learning and reinstatement of a previously learned response after extinction is a simple, well-validated measure of both acquisition of a rewarded instrumental response and sensitivity to reward and reward-associated cues. We investigated the effects of PAE on learning, extinction, and reinstatement of a simple instrumental response for food reward. Next, we assessed the effectiveness of an early intervention, communal nest (CN) housing, on increased reinstatement of an extinguished response seen after PAE. METHODS: To assess the effects of PAE on control over reward seeking, we tested male and female PAE and saccharine (SAC) controls raised in a standard nest (SN) on the acquisition, extinction, and food reward-induced reinstatement of an instrumental response utilizing a touch screen-based paradigm. Next, in order to examine the effects of an early-life intervention on these behaviors, we tested PAE and SAC mice raised in a CN early-life environment on these behaviors. RESULTS: PAE mice readily acquired and extinguished a simple touch response to a white square stimulus. However, PAE mice showed significantly increased and persistent reinstatement compared to controls. Increased maternal care via rearing in CN slowed acquisition and sped extinction learning and rescued the significantly increased reinstatement responding in PAE mice. CONCLUSIONS: Together these results demonstrate that even moderate PAE is sufficient to alter control over reward seeking as measured by reinstatement. Importantly, an early-life intervention previously shown to improve cognitive outcomes in PAE mice was sufficient to ameliorate this effect.

Sleep and new media usage in toddlers.

Several studies over the years have demonstrated the association between lack of sleep in children and certain physical, psychological, and behavioral disorders. The aim of this study was to disentangle the association between new screen-based electronic devices and sleep problems in toddlers, adjusting for other covariates already known to be associated with sleep quality. We conducted a cross-sectional study with the aid of a national sample of 1117 toddlers. Parents reported children's sleeping habits such as total sleep time and sleep onset latency, recreational activities, bedtime routines, and temperament. An ordered logistic regression was run to assess the associations between new media exposure and two sleep outcomes (total sleep time and sleep onset latency). Everyday use of a tablet or smartphone raised the odds of a shorter total sleep time (OR 1.95 [1.00-3.79], p < 0.05) and a longer sleep onset latency (OR 2.44 [1.26-4.73] p < 0.05) irrespective of other factors, such as temperament (restlessness, sociability), or traditional screen exposure (watching TV or playing videogames).Conclusion: New media usage is a factor associated in toddlers with sleeping fewer hours and taking longer to fall asleep, irrespective of other confounding factors. What is known • Studies have found an association between sleep behavior and the use of computers and video games in early childhood. • The blue light emitted from TV screens suppresses endogenous melatonin. What is new • The study found an association between daily new media (tablet and smartphone) usage and sleep quality in toddlers • New media usage exposes toddlers to the risk of fewer hours of sleep and taking longer to fall asleep, irrespective of other factors.

Appetitive to aversive counter-conditioning as intervention to reduce reinstatement of reward-seeking behavior: the role of the serotonin transporter.

Counter-conditioning can be a valid strategy to reduce reinstatement of reward-seeking behavior. However, this has not been tested in laboratory animals with extended cocaine-taking backgrounds nor is it well understood, which individual differences may contribute to its effects. Here, we set out to investigate the influence of serotonin transporter (5-HTT) genotype on the effectiveness of counter-conditioning after extended access to cocaine self-administration. To this end, 5-HTT+/+ and 5-HTT-/- rats underwent a touch screen-based approach to test if reward-induced reinstatement of responding to a previously counter-conditioned cue is reduced, compared with a non-counter-conditioned cue, in a within-subject manner. We observed an overall extinction deficit of cocaine-seeking behavior in 5-HTT-/- rats and a resistance to punishment during the counter-conditioning session. Furthermore, we observed a significant decrease in reinstatement to cocaine and sucrose associated cues after counter-conditioning but only in 5-HTT+/+ rats. In short, we conclude that the paradigm we used was able to produce effects of counter-conditioning of sucrose seeking behavior in line with what is described in literature, and we demonstrate that it can be effective even after long-term exposure to cocaine, in a genotype-dependent manner.

"From the moment I wake up I will use it every day, very hour": a qualitative study on the patterns of adolescents' mobile touch screen device use from adolescent and parent perspectives.

BACKGROUND: The use of mobile touch screen devices, e.g. smartphones and tablet computers, has become increasingly prevalent among adolescents. However, little is known about how adolescents use these devices and potential influences on their use. Hence, this qualitative study explored adolescents' perceptions on their patterns of use and factors influencing use, and perceptions and concerns from parents. METHODS: Semi-structured interviews were conducted with adolescents (n = 36; 11 to 18 years) and their parents/caregivers (n = 28) in Singapore recruited to represent males and females across a range of ages from different socioeconomic groups. Prompts covered weekday and weekend use patterns, types of activities, perspectives on amount of use, parental control measures and concerns. Interviews were recorded and transcribed. Transcripts were coded and thematic analysis was carried out. RESULTS: Smartphone was the most common mobile device owned and used by many of the adolescents, while only some used a tablet. Many adolescents and their parents felt that adolescents' MTSD use was high, frequent and ubiquitous, with frequent checking of device and multitasking during use. Reported influences of use included functional, personal and external influences. Some of the influences were irresistibility of mobile devices, lack of self-control, entertainment or relaxation value, and high use by peers, family and for schoolwork that contributed to high use, or school/parental control measures and lack of internet availability that limited use. Most adolescents were generally unconcerned about their use and perceived their usage as appropriate, while most parents expressed several concerns about their adolescents' use and perceived their usage as excessive. CONCLUSIONS: This study has provided rich insights into the patterns and influences of contemporary mobile device use by adolescents. Mobile device use has become an integral part of adolescents' daily routines, and was affected by several functional, personal and external influences which either facilitated or limited their use. There also seemed to be a strong inclination for adolescents to frequently check and use their mobile devices. There is an urgent need to understand the implications of these common adolescent behaviours to inform advice for wise mobile device use by adolescents.

Mobile touch screen device use and associations with musculoskeletal symptoms and visual health in a nationally representative sample of Singaporean adolescents.

This study aimed to describe contemporary technology use, especially smartphones and tablets (mobile touch screen devices), and examine associations with musculoskeletal symptoms and visual health among adolescents in Singapore. A representative sample of 1884 adolescents (50.4% girls) from grades primary 5 to post-secondary (10-18 years old), recruited from 13 schools, completed an online questionnaire in class. Total technology use was high, with smartphone duration being highest (mean = 264 [SD = 243] min/day). Patterns of use, including multitasking and bout length, were influenced by gender, school level, type of device and activities. Musculoskeletal discomfort and visual symptoms were commonly reported. After adjusting for potential confounders, more hours/day of smartphone use was associated with increased risk of neck/shoulders, upper back, arms and wrist/hand discomfort (OR = 1.04[95%CI = 1.01-1.07] to 1.07[1.03-1.10]) and visual symptoms (OR = 1.05[1.02-1.08]), but was associated with decreased odds of myopia (OR = 0.97[0.94-0.99]). No significant associations were found for tablet use. Practitioner Summary: 1884 adolescents in Singapore completed an in-depth questionnaire regarding their use of technology. The smartphone was the device with the highest usage, and greater smartphone use was associated with increased odds of musculoskeletal and visual symptoms. High use of smartphones has physical health implications for adolescents.

Enhanced cognition and dysregulated hippocampal synaptic physiology in mice with a heterozygous deletion of PSD-95.

PSD-95 is one of the most abundant proteins of the postsynaptic density of excitatory synapses. It functions as the backbone of protein supercomplexes that mediate signalling between membrane glutamate receptors and intracellular pathways. Homozygous deletion of the Dlg4 gene encoding PSD-95 was previously found to cause a profound impairment in operant and Pavlovian conditioning in Dlg4-/- mice studied in touch screen chambers that precluded evaluation of PSD-95's role in shaping more subtle forms of learning and memory. In this study, using a battery of touch screen tests, we investigated cognitive behaviour of mice with a heterozygous Dlg4 mutation. We found that in contrast to learning deficits of Dlg4-/- mice, Dlg4+/- animals demonstrated enhanced performance in the Visual Discrimination, Visual Discrimination Reversal and Paired-Associates Learning touch screen tasks. The divergent directions of learning phenotypes observed in Dlg4-/- and Dlg4+/- mice also contrasted with qualitatively similar changes in the amplitude and plasticity of field excitatory postsynaptic potentials recorded in the CA1 area of hippocampal slices from both mutants. Our results have important repercussions for the studies of genetic models of human diseases, because they demonstrate that reliance on phenotypes observed solely in homozygous mice may obscure qualitatively different changes in heterozygous animals and potentially weaken the validity of translational comparisons with symptoms seen in heterozygous human carriers.