Structural connectivity between the hippocampus and cortical/subcortical area relates to cognitive impairment in schizophrenia but not in mood disorders

Cognitive impairment in schizophrenia and other psychiatric disorders is a challenge to be overcome in order to maintain patients' quality of life and social function. The neurological pathogenesis of cognitive impairment requires further elucidation. In general, the hippocampus interacts between the cortical and subcortical areas for information processing and consolidation and has an important role in memory. We examined the relationship between structural connectivity of the hippocampus and cortical/subcortical areas and cognitive impairment in schizophrenia, major depressive disorder and bipolar disorder. Subjects comprised 21 healthy controls, 19 patients with schizophrenia, 20 patients with bipolar disorder and 18 patients with major depressive disorder. Diffusion-weighted tensor images data were processed using ProbtrackX2 to calculate the structural connectivity between the hippocampus and cortical/subcortical areas. Cognitive function was assessed using the Brief Assessment of Cognition in schizophrenia composite score. Hippocampal structural connectivity index was significantly correlated with composite score in the schizophrenia group but not in the healthy control, major depressive disorder or bipolar disorder groups. There were no statistically significant differences in hippocampal structural connectivity index between the four groups. Structural connectivity between the hippocampus and cortical/subcortical areas is suggested to be a pathophysiological mechanism of comprehensive cognitive impairment in schizophrenia.     

Cultural variations in optimistic and pessimistic bias: do Easterners really expect the worst and Westerners really expect the best when predicting future life events?

The authors compared levels of optimistic and pessimistic bias in the prediction of positive and negative life events between European Americans and Japanese. Study 1 showed that European Americans compared with Japanese were more likely to predict positive events to occur to self than to others. The opposite pattern emerged in the prediction of negative events. Study 2 replicated these cultural differences. Furthermore, positive associations emerged between predictions and occurrence of life events 2 months later for both European Americans and Japanese. Across both studies, results of within-groups analyses indicated that both groups expected negative events to be more likely to occur to others than to self (optimistic bias). In addition, Japanese expected positive events to be more likely to occur to others than to self (pessimistic bias). However, European Americans failed to show the expected optimistic bias for positive events.     

Development and Validation of the Female Muscularity Scale

Socially promoted physical appearance ideals for women place increasing importance on muscularity, resulting in growing muscularity concerns among traditional college-age women. To date, however, instruments for assessing the type of muscularity concerns reported by women are lacking. The aim of the present study was therefore to develop such a scale and examine its psychometric properties among a sample of young women. Findings from an exploratory factor analysis (n = 235) and a confirmatory factor analysis (n = 130) revealed a two-factor structure, including a five-item Attitudes subscale (α = .89) and a five-item Behaviors subscale (α = .90), which were moderately correlated, r = .50. In addition, the scale demonstrated good 2-week test-retest reliability (r = .76), and the subscales revealed moderate-to-large associations with body image concerns, drive for thinness, and exercise engagement, indicating concurrent validity. Thus the new Female Muscularity Scale is a useful and promising tool for assessing muscularity concerns among young women, and it may help toward understanding the role of pressures to achieve a toned body in the development of body image, eating, and exercise disorders.     

Sequential learning and rule abstraction in Bengalese finches

The Bengalese finch (Lonchura striata var. domestica) is a species of songbird. Males sing courtship songs with complex note-to-note transition rules, while females discriminate these songs when choosing their mate. The present study uses serial reaction time (RT) to examine the characteristics of the Bengalese finches’ sequential behaviours beyond song production. The birds were trained to produce the sequence with an “A–B–A” structure. After the RT to each key position was determined to be stable, we tested the acquisition of the trained sequential response by presenting novel and random three-term sequences (random test). We also examined whether they could abstract the embedded rule in the trained sequence and apply it to the novel test sequence (abstract test). Additionally, we examined rule abstraction through example training by increasing the number of examples in baseline training from 1 to 5. When considered as (gender) groups, training with 5 examples resulted in no statistically significant differences in the abstract tests, while statistically significant differences were observed in the random tests, suggesting that the male birds learned the trained sequences and transferred the abstract structure they had learned during the training trials. Individual data indicated that males, as opposed to females, were likely to learn the motor pattern of the sequence. The results are consistent with observations that males learn to produce songs with complex sequential rules, whereas females do not.     

Characteristics of serial order learning in common marmosets (Callithrix jacchus)

We investigated the characteristics of serial order learning in common marmosets (Callithrix jacchus). Five marmosets were trained in a sequential responding task in which they were required to touch four graphic patterns in a given order (A→B→C→D) to obtain a reward. All five marmosets learned the task with over 65% accuracy. Shuffling the positions of B, C, and D immediately after the marmoset had correctly identified and selected the first stimulus (A) either decreased accuracy or lengthened response latency for the second stimulus (B). These results suggest that the marmosets planned the response to the second stimulus before they touched the first stimulus. In addition, when we presented a pair of stimuli (AB, AC, AD, BC, BD, and CD pairs), the marmosets responded to the stimuli in the pair in the appropriate order, according to the learned order (A→B→C→D). The analyses of first and second response latencies clearly demonstrated both the first-item and missing-item effects in task performance. Our data provide direct evidence that marmosets can learn the relative order of the four stimuli in a sequential responding task. (PsycINFO Database Record (c) 2012 APA, all rights reserved).     

Developmental trajectory in the relationship between calculation skill and finger dexterity: A longitudinal study

A 2‐year longitudinal study of 33 children aged 4–6 years was conducted to clarify the developmental relationship between calculation skill and finger dexterity, as well as the selectivity of the predictive power of finger dexterity on later calculation skill. We examined individual developmental change in the relationship between addition performance and finger dexterity and observed whether children fit a linear developmental pattern. Multiple regression analysis showed that participants' performance on addition tests was strongly predicted by their finger dexterity. However, their performance on vocabulary tests was not strongly influenced by finger dexterity. These findings suggest that calculation skill in children aged 4–6 years is strongly related to finger dexterity.     

Individual identity and affective valence in marmoset calls: in vivo brain imaging with vocal sound playback

As with humans, vocal communication is an important social tool for nonhuman primates. Common marmosets (Callithrix jacchus) often produce whistle-like ‘phee’ calls when they are visually separated from conspecifics. The neural processes specific to phee call perception, however, are largely unknown, despite the possibility that these processes involve social information. Here, we examined behavioral and whole-brain mapping evidence regarding the detection of individual conspecific phee calls using an audio playback procedure. Phee calls evoked sound exploratory responses when the caller changed, indicating that marmosets can discriminate between caller identities. Positron emission tomography with [¹⁸F] fluorodeoxyglucose revealed that perception of phee calls from a single subject was associated with activity in the dorsolateral prefrontal, medial prefrontal, orbitofrontal cortices, and the amygdala. These findings suggest that these regions are implicated in cognitive and affective processing of salient social information. However, phee calls from multiple subjects induced brain activation in only some of these regions, such as the dorsolateral prefrontal cortex. We also found distinctive brain deactivation and functional connectivity associated with phee call perception depending on the caller change. According to changes in pupillary size, phee calls from a single subject induced a higher arousal level compared with those from multiple subjects. These results suggest that marmoset phee calls convey information about individual identity and affective valence depending on the consistency or variability of the caller. Based on the flexible perception of the call based on individual recognition, humans and marmosets may share some neural mechanisms underlying conspecific vocal perception.     

Do the upright eyes have it?

Eye contact is crucial for social communication. A perceived direct gaze facilitates detection, whereas face inversion diminishes this facilitative effect (Senju, Hasegawa, & Tojo, 2005). In the present study, we adopted a visual search paradigm to investigate why a direct gaze facilitates detection in an upright face, but not in an upside-down face. Upright eyes were found to facilitate detection even when other parts of the face were inverted or absent, whereas inverted eyes had no effect on search performance. A critical role for the morphological information of upright eyes, which can be distorted by “eye inversion,” in direct gaze processing is suggested.     

Infants’ recognition of objects using canonical color

We explored infants’ ability to recognize the canonical colors of daily objects, including two color-specific objects (human face and fruit) and a non-color-specific object (flower), by using a preferential looking technique. A total of 58 infants between 5 and 8 months of age were tested with a stimulus composed of two color pictures of an object placed side by side: a correctly colored picture (e.g., red strawberry) and an inappropriately colored picture (e.g., green-blue strawberry). The results showed that, overall, the 6- to 8-month-olds showed preference for the correctly colored pictures for color-specific objects, whereas they did not show preference for the correctly colored pictures for the non-color-specific object. The 5-month-olds showed no significant preference for the correctly colored pictures for all object conditions. These findings imply that the recognition of canonical color for objects emerges at 6 months of age.     

Tools for the body (schema)

What happens in our brain when we use a tool to reach for a distant object? Recent neurophysiological, psychological and neuropsychological research suggests that this extended motor capability is followed by changes in specific neural networks that hold an updated map of body shape and posture (the putative "Body Schema" of classical neurology). These changes are compatible with the notion of the inclusion of tools in the "Body Schema", as if our own effector (e.g. the hand) were elongated to the tip of the tool. In this review we present empirical support for this intriguing idea from both single-neuron recordings in the monkey brain and behavioural performance of normal and brain-damaged humans. These relatively simple neural and behavioural aspects of tool-use shed light on more complex evolutionary and cognitive aspects of body representation and multisensory space coding for action.