Right hemispatial neglect: frequency and characterization following acute left hemisphere stroke

The frequency of various types of unilateral spatial neglect and associated areas of neural dysfunction after left hemisphere stroke are not well characterized. Unilateral spatial neglect (USN) in distinct spatial reference frames have been identified after acute right, but not left hemisphere stroke. We studied 47 consecutive right handed patients within 48h of left hemisphere stroke to determine the frequency and distribution of types of right USN using cognitive testing and MRI imaging. The distribution of USN types was different from the previously reported distribution following acute right hemisphere stroke. In this left hemisphere stroke population, allocentric neglect was more frequent than egocentric neglect.     

Detection of emotional expressions in rapidly changing facial displays in high- and low-socially anxious women

Facial information and attention to facial displays are distributed over spatial as well as temporal domains. Thus far, research on selective attention to (dis)approving faces in the context of social anxiety has concentrated primarily on the spatial domain. Using a rapid serial visual presentation (RSVP) paradigm, the present study examined the temporal characteristics of visual attention for happy and angry faces in high- (n=16) and low-socially anxious individuals (n=17), to test whether also in the temporal domain socially anxious individuals are characterized by threat-confirming attentional biases. Results indicated that presenting angry faces as the first target (T1) did not aggravate the detection of the emotional expression of the second target (T2). Yet, participants generally showed superior detection of the emotional expression of T2, if T2 was an angry face. Casting doubt on the role of such attenuated attentional blink for angry faces in social anxiety, no evidence emerged to indicate that this effect was relatively strong in high-socially anxious individuals. Finally, the presentation of an angry face as T2 resulted in a relatively hampered identification of a happy-T1. Again, this "backward blink" was not especially pronounced in high-socially anxious individuals. The present anger superiority effects are consistent with evolutionary models stressing the importance of being especially vigilant for signals of dominance. Since the effects were not especially pronounced in high-anxious individuals, the present study adds to previous findings indicating that socially anxious individuals are not characterized by a bias in the (explicit) detection of emotional expressions [Philippot, P., & Douilliez, C. (2005). Social phobics do not misinterpret facial expression of emotion. Behaviour Research and Therapy, 43, 639-652].     

Re-evaluating evidence for linguistic relativity: reply to Boroditsky (2001)

Six unsuccessful attempts at replicating a key finding in the linguistic relativity literature [Boroditsky, L. (2001). Does language shape thought?: Mandarin and English speakers' conceptions of time. Cognitive Psychology, 43, 1-22] are reported. In addition to these empirical issues in replicating the original finding, theoretical issues present in the original report are discussed. In sum, we conclude that Boroditsky (2001) provides no support for the Whorfian hypothesis.     

Recent Innovative Studies of Memory in Temporal Lobe Epilepsy

Investigations of patients with temporal lobe epilepsy continue to result in significant advancements in the neuroscience of human memory, as they have for over 50 years. Recent reviews describing the state of the art in the clinical neuropsychology of TLE generally have emphasized (1) lateralization of cognitive deficits and the material-specific model of memory and/or (2) the relationships among pre- and post-surgery performance on standardized measures of anterograde memory, demographic and epilepsy variables and neuroimaging, neuropathology, and neurosurgery data. As information continues to accumulate about the pattern of performance on standard laboratory memory tests and the implications of these data before and after anterior temporal lobectomy for the treatment of TLE, innovative assessment techniques also are increasingly being applied. This review focuses on English language publications that addressed selected novel topics in adult TLE memory research. These topics are: (1) remote memory; (2) accelerated forgetting or long term amnesia; and (3) lateral versus mesial temporal lobe contributions to memory.     

Children's early productivity with verbal morphology

Three studies using the intermodal preferential looking paradigm examined onset of productive comprehension of tense/aspect morphology in English. When can toddlers understand these forms with novel verbs and novel events? The first study used familiar verbs and showed that 26–36-month olds correctly matched a past/perfective form (-ed or irregular past) to a completed version of an event and a present/imperfective (is V-ing) to the ongoing version of the same event. The second study used novel verbs and events and found that 33-month olds failed to use tense/aspect morphology to choose between completed and ongoing versions of the same event. The third study also used novel verbs and events but simplified the processing demands of the task in several ways (using initial priming of the events and classes of meaning, using different events within test pairs). This study found that 30-month olds successfully used tense/aspect morphology to choose between ongoing and completed novel events. The results demonstrate that children have productive command of tense/aspect morphology by 30 months and have therefore begun the process of creating an abstract grammar containing this element.     

Short-term gains, long-term pains: How cues about state aid learning in dynamic environments

Successful investors seeking returns, animals foraging for food, and pilots controlling aircraft all must take into account how their current decisions will impact their future standing. One challenge facing decision makers is that options that appear attractive in the short-term may not turn out best in the long run. In this paper, we explore human learning in a dynamic decision making task which places short- and long-term rewards in conflict. Our goal in these studies was to evaluate how people’s mental representation of a task affects their ability to discover an optimal decision strategy. We find that perceptual cues that readily align with the underlying state of the task environment help people overcome the impulsive appeal of short-term rewards. Our experimental manipulations, predictions, and analyses are motivated by current work in reinforcement learning which details how learners value delayed outcomes in sequential tasks and the importance that “state” identification plays in effective learning.     

The role of the right posterior parietal cortex in temporal order judgment

Perceived order of two consecutive stimuli may not correspond to the order of their physical onsets. Such a disagreement presumably results from a difference in the speed of stimulus processing toward central decision mechanisms. Since previous evidence suggests that the right posterior parietal cortex (PPC) plays a role in modulating the processing speed of a visual target, we applied single-pulse TMS over the region in 14 normal subjects, while they judged the temporal order of two consecutive visual stimuli. Stimulus-onset-asynchrony (SOA) randomly varied between -100 and 100 ms in 20-ms steps (with a positive SOA when a target appeared on the right hemi-field before the other on the left), and a point of subjective simultaneity was measured for individual subjects. TMS stimulation was time-locked at 50, 100, 150, and 200 ms after the onset of the first stimulus, and results in trials with TMS on right PPC were compared with those in trials without TMS. TMS over the right PPC delayed the detection of a visual target in the contralateral, i.e., left hemi-field by 24 (+/-7 SE) ms and 16 (+/-4 SE) ms, when the stimulation was given at 50 and 100 ms after the first target onset. In contrast, TMS on the left PPC was not effective. These results show that the right PPC is important in a timely detection of a target appearing on the left visual field, especially in competition with another target simultaneously appearing in the opposite field.     

Back to the future: Temporal perspective in the explanation of events

Prospective hindsight involves generating an explanation for a future event as if it had already happened; i.e., one goes forward in time, and then looks back. In order to examine how shifts in perspective might influence people's perceptions of events, we investigated two possible factors: temporal perspective (whether an event is set in the future or past) and uncertainty (whether the event's occurrence is certain or uncertain). In the first experiment, temporal perspective showed little influence while outcome uncertainty strongly affected the nature of explanations for events. Explanations for sure events tended to be longer, to contain a higher proportion of episodic reasons, and to be expressed in past tense. Evidence from the second experiment supports the view that uncertainty mediates not the amount of time spent explaining, but rather subjects' choice of explanation type. The implications of these findings for the use of temporal perspective in decision aiding are discussed.     

Predicting a changing taste: Do people know what they will like?

A distinction is made between decision utility, experienced utility, and predicted utility and an experiment is reported addressing people's ability to forecast experienced utility. Subjects in two experiments made predictions of their future liking for stimuli to which they were then exposed daily for one week. The stimuli were ice cream in a pilot study, plain yogurt in the main study, and short musical pieces in both studies. Decreased liking was the modal prediction, even when the true outcome was increased liking, or reduced dislike. There was substantial stability of tastes, but there were also substantial individual differences in the size and even the sign of changes in liking with repeated exposure. There was little or no correlation between the predictions of hedonic change that individuals made and the changes they actually experienced.     

The temporal–hippocampal region and retention: The role of temporo-entorhinal connections in rats

Results from previous studies suggest that the entorhinal cortex may be involved in mnemonic processes. The present study was carried out to investigate whether disruption of fibre connections between the temporal cortex and lateral entorhinal area may impair retention of a pre-operatively acquired simultaneous brightness discrimination task. The lesion resulted in a severe impairment in retaining the discrimination task (Experiment 1). The retention deficit could not be traced into the hippocampal formation by making perforant path lesions or hippocampal lesions (Experiment 2). The results indicate that the lateral entorhinal cortex is more crucial for reference memory than the hippocampal formation.