Azizuddin Khan

Auditory event-related potentials show altered hemispheric responses in dyslexia.

Dyslexia is characterized by deficits in phonological processing abilities. However, it is unclear what the underlying factors for poor phonological abilities or speech sound representations are. One hypothesis suggests that individuals with dyslexia have problems in basic acoustic perception which in turn can also cause problems in speech perception. Here basic auditory processing was assessed by auditory event-related potentials recorded for paired tones presented in an oddball paradigm in 9-year-old children with dyslexia and a familial background of dyslexia, typically reading children at familial risk for dyslexia and control children without risk for dyslexia. The tone pairs elicited a P1-N250 complex with emerging N1-P2 complex. Control children showed larger responses over the left-than-right hemisphere at the P1 and P2 time windows for both short and long within-pair intervals (WPI; 10 and 255ms) whereas children with dyslexia showed this pattern only for the tone pairs with the long WPI. The response for the pairs with the short WPI showed equal amplitudes over both hemispheres in children with dyslexia. The findings indicate that individuals with dyslexia process basic auditory information differently when the tones are within the temporal window of integration.

Attention, polychronicity, and expertise in prospective memory performance: Programmers' vulnerability to habit intrusion error in multitasking

The paper examines prospective memory (ProM) in programmer multitasking and reports administration of a naturalistic atypical action. The study emphasizes on how attention, time orientation, and expertise affect ProM performance in multitasking among a group of computer science and engineering students (N=108). The results suggest that attention play a crucial role in multitasking and ProM performance with respect to whether or not a word display requires more attention to be devoted in monitoring and identifying it for an appropriate action. Polychrons exhibit lesser degree of ProM performance failure than monochrons whereas expertise does not have an effect. Finally, results show that out of overall ProM performance failure, habit intrusion errors comprise of 16.22% occurring 1.75 times in every 10 valid click responses of ProM task. Moreover, experts demonstrate a superior performance over novices in programming.

An investigation into prospective memory in children with developmental dyslexia

Developmental dyslexia hinders reading and writing acquisition of around 5–10% of the children all over the world. However, little is known about role of prospective memory among dyslexics. Prospective memory is realization of delayed intention. Realization of delayed intention requires self initiated process. The present study explored the role of memory (prospective and retrospective memory), meta-memory and attention among dyslexics children. One hundred and fifteen children (51 dyslexics and 64 normal controls) participated in the study. Prospective and retrospective memory questionnaire, everyday attention questionnaire and meta-memory were administered on children. Analysis of variance was used to analyses the data. All the main effects were significant. Some interactions were also found to be significant. Results suggest that dyslexics performance on memory (prospective and retrospective memory) was worse than normal control. Meta-memory influences both dyslexics and normal control on prospective and retrospective memory. However, meta-memory affected dyslexics much more than normal control group. Similarly, significant differential effects were observed for simple, difficult and mixed attentional condition among between dyslexics and normal control. Dyslexics performance was deteriorated as compared to normal control group. The findings of the study are discussed in the light of the existing literature.

Decision Making in the Reward and Punishment Variants of the Iowa Gambling Task: Evidence of “Foresight” or “Framing”?

Surface-level differences in the reward and punishment variants, specifically greater long-term decision making in the punishment variant of the Iowa Gambling Task (IGT) observed in previous studies led to the present comparison of long-term decision making in the two IGT variants (n = 320, male = 160). It was contended that risk aversion triggered by a positive frame of the reward variant and risk seeking triggered by a negative frame of the punishment variant appears as long-term decision making in the two IGT variants. Apart from the frame of the variant as a within-subjects factor (variant type: reward and punishment), the order in which the frame was triggered (order type: reward–punishment or punishment–reward), and the four types of instructions that delineated motivation toward reward from that of punishment (reward, punishment, reward and punishment, and no-hint) were hypothesized to have an effect on foresighted decision making in the IGT. As expected, long-term decision making differed across the two IGT variants suggesting that the frame of the variant has an effect on long-term decision making in the IGT (p < 0.001). The order in which a variant was presented, and the type of the instructions that were used both had an effect on long-term decision making in the two IGT variants (p < 0.05). A post hoc test suggested that the instructions that differentiated between reward and punishment resulted in greater foresight than the commonly used IGT instructions that fail to distinguish between reward and punishment. As observed in previous studies, there were more number of participants (60%) who showed greater foresight in the punishment variant than in the reward variant (p < 0.001). The results suggest that foresight in IGT decision making is sensitive to reward and punishment frame in an asymmetric manner, an observation that is aligned with the behavioral decision making framework. Benefits of integrating findings from behavioral studies in decision neuroscience are discussed, and a need to investigate cultural differences in the IGT studies is pointed out.

An examination of the leftward cradling bias among typically developing adults high on autistic traits.

The leftward cradling bias is the tendency to cradle infants on the left side of the body and it has been linked with hemispheric asymmetry for emotional processing. This study examines this phenomenon using a real-size infant doll in typically developing adults who score high in the Reading the Mind in the Eyes, the Autistic Spectrum Quotient and the Empathy Quotient, measures that assess autistic traits among typically developing individuals. Results revealed that this group showed a reduced tendency to cradle on the left compared to participants who score within the normal range on the above measurements. This study provides further support for the justification of the leftward cradling bias upon brain lateralization on emotional processing. Study limitations and suggestions for future research are discussed.

Effect of Vitamin E Administration on Learning of the Young Male Rats

The effect of vitamin E intake on spatial learning and working memory performances of young rats has been investigated in the Morris water maze and locomotor activity has been assessed by an open-field test. A total of 45 young male Wistar albino rats aged two months were divided into three equal groups: control, olive oil, and vitamin E groups. These groups were treated for 30 days with a once daily intraperitoneal injection. The rats were then tested for their ability to find the location of the platform (spatial learning). The results revealed that there was no statistically significant difference between the time spent to find the platform and the time spent in half area of the tank, including the platform among the group, while the time spent to find the platform was found to have increased from the first day to the fourth day in all the groups. In the open-field test, the locomotor activity quite significantly increased in the peripheral area in the olive oil group. The supplementation with vitamin E for a short period had not improved the learning performance of the healthy young rats. It was concluded that the beneficial effect of vitamin E intake on learning is related to the beginning time and the duration of vitamin E intake.

The Measurement of Negative Creativity: Metrics and Relationships

Although the dark side of creativity and negative creativity are shaping into legitimate subconstructs, measures to assess the same remain to be validated. To meet this goal, two studies assessed the convergent, predictive, and criterion-related validities of two valence-inclusive creativity measures. One measure assessed the self-report endorsement of social creativity, and the other was an Alternate Uses Test (AUT) assessing generation of nonsocial creativity. Participants (N = 129, 88 women, Mage = 25.09 years, SD = 10.03) completed the two creativity measures and three Dark Triad personality scales (narcissism, psychopathy, Machiavellianism) through an online form. Correlations and multiple regressions were employed in the studies. Study 1 assessed the convergent and predictive validities between the two measures. Results indicated a strong convergence on the measurement of positive creativity, but not on negative creativity. Study 2 used the Dark Triad of personality as an external criterion to evaluate the criterion-related validity of the measurement of negative creativity. Although the Dark Triad predicted the self-reported endorsement of negative creativity, there was no discernable relationship with the generation of negative-creative responses on the AUT. Implications of current results, and suggestions for future metrics of valence-inclusive creativity are discussed.

Hemispheric specialization of impaired disengagement of attention in depression: a tachistoscopic method

ABSTRACT Difficulty shifting attention away from negative stimuli once engaged is a well-established cognitive bias observed in depression. This study attempted to determine whether this impaired disengagement of attention is lateralized in the brain. Thirty depressed and 30 control participants performed an attention disengagement task wherein the valence of the stimulus and the visual field was presented. The depressed group had longer reaction times than the control group, indicative of the typical cognitive and psychomotor slowing seen in depression. The effect of visual field presentation on the ability to disengage attention however was different for controls as compared to the patients. In controls, a distinct right hemisphere advantage was seen for disengaging attention which is in line with research that has identified right hemisphere structures as the seat of behavioural inhibition. In the depressed group, however, this right hemisphere advantage was not observed.

Interval timing predicts impulsivity in intertemporal choice: combined behavioral and drift-diffusion model evidence

ABSTRACT This study investigated the relationship between interval timing and impulsivity in intertemporal choice in a healthy population. A duration production task was used to assess interval timing. Choice impulsivity was assessed using a hypothetical money choice task. Results from 134 participants indicated that faster internal clock significantly predicted lower choice impulsivity. A subsequent drift-diffusion model analysis of the behavioural data revealed that in the sub-group of relatively farsighted participants, faster internal clock predicted consideration of more information before making a choice, which in turn was associated with lower choice impulsivity. In the sub-group of relatively impatient participants too, faster internal clock predicted consideration of more information, but which in turn was associated with higher choice impulsivity. It is concluded that among relatively farsighted individuals in a normal population, faster internal clock favours a more deliberate processing of the options at hand, thus eliciting less impulsive choices.

Brain Lateralization of Emotional Processing in Depression

There are three major hypotheses regarding the lateralization of emotion in the brain— the right-hemisphere hypothesis (RHH), the valence hypothesis, and the approachwithdrawal hypothesis. The approach-withdrawal hypothesis, which is the most widely accepted, states that emotions that elicit approach behaviors are lateralized to the left hemisphere, while emotions that elicit withdrawal behaviors are lateralized to the right hemisphere. In line with this hypothesis, it has been found that persons with depression show left frontal hypoactivity and right frontal hyperactivity. This hemispheric asymmetry appears not to influence mood but rather emotional reactions to affective stimuli. That is, a person with such an asymmetry does not show a predominant negative mood, but rather heightened negative reactions to occurrences in the environment. The asymmetry may also be a biological marker of depression, with research evidence that it is found in remitted depressives and in infants of depressed mothers. Currently, research in this area focuses on identifying the mechanism underlying the link between the asymmetry and depression.