Spatial orienting of tactile attention induced by social cues

Several studies have established that humans orient their visual attention reflexively in response to social cues such as the direction of someone else’s gaze. However, the consequences of this kind of orienting have been addressed only for the visual system. We investigated whether visual social attention cues can induce shifts in tactile attention by combining a central noninformative eye-gaze cue with tactile targets presented to participants’ fingertips. Data from speeded detection, speeded discrimination, and signal detection tasks converged on the same conclusion: Eye-gaze-based orienting facilitates the processing of tactile targets at the location of the gazed-at body location. In addition, we examined the effects of other directional cues, such as conventional arrows, and found that they can be equally effective. This is the first demonstration that social attention cues have consequences that reach beyond their own sensory modality.     

Effects of the menstrual cycle on looking preferences for faces in female rhesus monkeys

Fluctuations of ovarian hormones across the menstrual cycle influence a variety of social and cognitive behaviors in primates. For example, female rhesus monkeys exhibit heightened interest for males and increased agonistic interactions with other females during periods of high estrogen levels. In the present study, we hypothesized that females’ preference for males during periods of high estrogen levels is also expressed at the level of face perception. We tested four intact females on two face-tasks involving neutral portraits of male and female rhesus monkeys, chimpanzees and humans. In the visual preference task (VP), monkeys had to touch a button to view a face image. The image remained on the screen as long as the button was touched, and the duration of pressing was taken as an index of the monkey's looking time for the face stimulus. In the Face-Delayed Recognition Span Test (Face-DRST), monkeys were rewarded for touching the new face in an increasing number of serially presented faces. Monkeys were tested 5 days a week across one menstrual cycle. Blood was collected every other day for analysis of estradiol and progesterone. Two of the four females were cycling at the time of testing. We did not find an influence of the cycle on Face-DRST, likely due to a floor effect. In the VP however, the two cycling individuals looked longer at conspecific male faces than female faces during the peri-ovulatory period of the cycle. Such effects were absent for human and chimpanzee faces and for the two noncycling subjects. These data suggest that ovarian hormones may influence females’ preferences for specific faces, with heightened preference for male faces during the peri-ovulatory period of the cycle. Heightened interest for stimuli of significant reproductive relevance during periods of high conception risk may help guide social and sexual behavior in the rhesus monkey.     

From prioritizing objects to prioritizing cues: a developmental shift for cognitive control

Emerging cognitive control supports increasingly adaptive behaviors and predicts life success, while low cognitive control is a major risk factor during childhood. It is therefore essential to understand how it develops. The present study provides evidence for an age‐related shift in the type of information that children prioritize in their environment, from objects that can be directly acted upon to cues signaling how to act. Specifically, gaze patterns recorded while 3‐ to 12‐year‐olds and adults engaged in a cognitive control task showed that whereas younger children fixated on targets that they needed to respond to before gazing at task cues signaling how to respond, older children and adults showed the opposite pattern (which yielded better performance). This shift in information prioritization has important conceptual implications, suggesting that a major force behind cognitive control development may be non‐executive in nature, as well as opening new directions for interventions.     

Mutation at the TrkB PLC{gamma}-docking site affects hippocampal LTP and associative learning in conscious mice

Previous in vitro studies have characterized the electrophysiological properties and molecular events associated with long-term potentiation (LTP), but as yet there are no in vivo data from molecular-level dissection that directly identify LTP as the biological substrate for learning and memory. Understanding whether the molecular pathways required for learning are also those generating LTP when measured directly on the relevant circuit of a learning animal is clearly important, although so far has proved technically difficult. Here, for the first time, we combine highly defined genetic mouse models with behavior and in vivo recordings. We recorded the activity-dependent changes taking place at the CA3-CA1 synapses during the acquisition and extinction of a simple form of an associative learning task in mice carrying point mutations on specific docking sites of TrkB receptors (trkB(SHC), trkB(PLC)). The learning task consisted of a classical eyeblink conditioning using a trace paradigm. The conditioned stimulus (CS) consisted of a tone and was followed by a periorbital electrical shock as an unconditioned stimulus (US). The US started 500 msec after the end of the CS. We show that a single pulse presented to the Schaffer collateral-commissural pathway during the CS-US interval evoked a monosynaptic field excitatory postsynaptic potential (fEPSP) at the CA1 pyramidal cells, with a slope linearly related to learning evolution in controls and trkB(SHC) mutants, but the relationship was impaired in trkB(PLC) mice. These data support a link between the PLCgamma-docking site downstream of TrkB and the activity-dependent synaptic changes evoked at the CA3-CA1 synapses during associative learning in conscious mice, and indicate that TrkB PLCgamma-site-activated molecular pathway(s) underlie both associative learning and LTP triggered at the CA3-CA1 synapse.     

Decision making is affected in obstructive sleep apnoea syndrome

We assessed decision making in 20 patients newly diagnosed with obstructive sleep apnoea (OSA) and 20 healthy controls with the Iowa Gambling Task (IGT), which evaluates the ability to learn to sacrifice immediate rewards in favour of long‐term gains. A standard neuropsychological battery was administered. Switching scores tended to be lower in patients. Patients persisted in selecting risky decks throughout the IGT, whereas controls behaved normally. Performance was correlated with hypoxaemia. Brain regions underlying decision making may be affected by OSA‐related hypoxaemia.     

Affective Priming Effects in the Left and Right Cerebral Hemispheres in Patients With Alzheimer's Disease

Alzheimer’s disease (AD) patients and control subjects were tested in an affective priming paradigm associated with an affective discrimination task. Two pictures, one affectively positive or affectively negative and the other neutral, were presented simultaneously in the right and in the left visual fields; the participants had to decide which of the two pictures was the most affectively positive or negative. The target pictures were preceded by a prime picture that was either affectively positive, affectively negative, or neutral. The principal result was the observation, in AD patients as well as in control subjects, of negative affective priming effects for targets presented in the right hemisphere, and of positive affective priming effects for targets presented in the left hemisphere. The presence of affective priming effects suggests that AD patients have no particular deficit in the automatic activation of emotional information; the fact that priming effects were also observed for targets presented in the left hemisphere showed that AD patients probably have no left hemisphere deficit in the automatic activation of emotional information. However, in AD patients, affective priming effects were significant with negative targets but not with positive targets, which could suggest that AD patients processed positive targets in a more semantic way than negative targets.     

Predictors of semantic categorical flexibility in older adults

This study investigated the processes involved in the aging of semantic categorical flexibility. A previous study revealed the effects of aging on the flexible use of taxonomic relations. We aimed to explain our previous results regarding the performance of older adults; we carried out investigations into the respective roles of executive and conceptual factors in semantic categorical flexibility. Fifty older adults carried out a semantic categorical flexibility task alongside conceptual and executive measures. The results replicate our previous findings and indicate that the predictors of the maintenance of the use of taxonomic relations are conceptual and the predictors of the switching from thematic to taxonomic relations are executive.     

The role of goal representation in preschoolers' flexibility and inhibition

This study addressed the role of goal representation in preschoolers’ inhibition and flexibility performance. A total of 56 4- and 5-year-olds were tested in an adapted version of the Shape School task where the difficulty of goal representation was manipulated by varying the degree of transparency of task cues. The findings showed that both age groups’ performance in the flexibility phase was increased when demands on goal representation were alleviated by using transparent cues instead of arbitrary cues. Furthermore, 4-year-olds performed more accurately on go trials in the inhibition phase with transparent cues than with arbitrary cues. These results confirm the critical role of goal representation in flexibility and reveal its influence in inhibition contexts. Altogether, this study suggests that goal representation is a key element for efficient executive function across a variety of settings involving different executive functions.     

The influence of stimulus-set size on developmental changes in cognitive control and conflict adaptation

Cognitive control abilities substantially improve from early childhood to adulthood. The primary aim of this study was to examine the influence of stimulus-set size on developmental changes in cognitive control abilities such as task switching, interference control, and conflict adaptation. We assumed that a small stimulus set used in a task-switching paradigm would induce stronger task-stimulus priming that might increase the need for control, thereby amplifying age differences in cognitive control abilities. Therefore, we compared task-switching performance in a group of participants responding to a small stimulus-set (N=4) with a group responding to a large stimulus-set (N=96) in three age groups: kindergarten children (4.1-6.0 years of age), elementary school children (6.1-9.0 years of age), and young adults (21.0-28.0 years of age) on conflicting vs. non-conflicting trials (interference control) and following conflicting vs. non-conflicting trials (conflict adaptation). Results on the basis of error rates support the view that a small stimulus-set size during task switching (i.e., larger task-stimulus priming) increases the need for control as we found (a) worse conflict adaptation on task-repetition trials only for small but not for large set sizes and (b) larger interference costs under small than large set-size condition for elementary school children as compared with young adults. Kindergarten children were less sensitive to the set-size manipulation and showed major problems in interference control while being in a task-switching situation, even if no actual task switch was required, possibly reflecting their inability to represent complex higher-order task rules.