Relationship of temporal lobe volumes to neuropsychological test performance in healthy children

Ecological validity of neuropsychological assessment includes the ability of tests to predict real-world functioning and/or covary with brain structures. Studies have examined the relationship between adaptive skills and test performance, with less focus on the association between regional brain volumes and neurobehavioral function in healthy children. The present study examined the relationship between temporal lobe gray matter volumes and performance on two neuropsychological tests hypothesized to measure temporal lobe functioning (visual perception-VP; peabody picture vocabulary test, third edition-PPVT-III) in 48 healthy children ages 5-18 years. After controlling for age and gender, left and right temporal and left occipital volumes were significant predictors of VP. Left and right frontal and temporal volumes were significant predictors of PPVT-III. Temporal volume emerged as the strongest lobar correlate with both tests. These results provide convergent and discriminant validity supporting VP as a measure of the "what" system; but suggest the PPVT-III as a complex measure of receptive vocabulary, potentially involving executive function demands.     

Hemispheric asymmetries for temporal information processing: transient detection versus sustained monitoring

This study investigated functional differences in the processing of visual temporal information between the left and right hemispheres (LH and RH). Participants indicated whether or not a checkerboard pattern contained a temporal gap lasting between 10 and 40 ms. When the stimulus contained a temporal signal (i.e. a gap), responses were more accurate for the right visual field-left hemisphere (RVF-LH) than for the left visual field-right hemisphere (LVF-RH). This RVF-LH advantage was larger for the shorter gap durations (Experiments 1 and 2), suggesting that the LH has finer temporal resolution than the RH, and is efficient for transient detection. In contrast, for noise trials (i.e. trial without temporal signals), there was a LVF-RH advantage. This LVF-RH advantage was observed when the entire stimulus duration was long (240 ms, Experiment 1), but was eliminated when the duration was short (120 ms, Experiment 2). In Experiment 3, where the gap was placed toward the end of the stimulus presentation, a LVF-RH advantage was found for noise trials whereas the RVF-LH advantage was eliminated for signal trials. It is likely that participants needed to monitor the stimulus for a longer period of time when the gap was absent (i.e. noise trials) or was placed toward the end of the presentation. The RH may therefore be more efficient in the sustained monitoring of visual temporal information whereas the LH is more efficient for transient detection.     

The flexibility of association between temporal concepts and physical space in the Japanese language

Previous studies have indicated that temporal concepts such as the past and future are associated with horizontal (left–right) space. This association has been interpreted as reflecting left‐to‐right writing systems. The Japanese language, however, is written both horizontally and vertically and, when texts are presented vertically, the sequence of columns runs from right to left. This study examines whether the associations between time and space are changed by the direction of the character strings using a word categorization task. Consistent with previous studies, response times and error rates indicated left‐past and right‐future associations when participants read words presented horizontally. On the other hand, response times indicated the opposite (i.e., left‐future and right‐past associations) when participants read words presented vertically. These results suggest that temporal concepts are not associated with one's body or physical space in an inflexible manner, but rather the associations can flexibly change through experience.     

Do you look to the future or focus on today? The impact of life experience on intertemporal decisions

In this research, we investigate the impact of significant life experiences on intertemporal decisions among young adults. A series of experiments focus specifically on the impact of experiencing the death of a close other by cancer. We show that such an experience, which bears information about time, is associated with making decisions that favor the long-term future over short-term interests (Studies 1 and 2). Underlying this effect appears to be increased salience and concreteness regarding one’s future life course, shifting focus away from the present toward the long run (Studies 3 and 4). Finally, we explore the shift caused by a cancer death of a public figure and examine its stability over time (Study 5). Implications for research on intertemporal decision making and the impact of life events on perceptions and preferences are discussed.     

Social laws in alternating time: effectiveness,feasibility, and synthesis

Since it was first proposed by Moses, Shoham, and Tennenholtz, the social laws paradigm has proved to be one of the most compelling approaches to the offline coordination of multiagent systems. In this paper, we make four key contributions to the theory and practice of social laws in multiagent systems. First, we show that the Alternating-time Temporal Logic (atl) of Alur, Henzinger, and Kupferman provides an elegant and powerful framework within which to express and understand social laws for multiagent systems. Second, we show that the effectiveness, feasibility, and synthesis problems for social laws may naturally be framed as atl model checking problems, and that as a consequence, existing atl model checkers may be applied to these problems. Third, we show that the complexity of the feasibility problem in our framework is no more complex in the general case than that of the corresponding problem in the Shoham–Tennenholtz framework (it is np-complete). Finally, we show how our basic framework can easily be extended to permit social laws in which constraints on the legality or otherwise of some action may be explicitly required. We illustrate the concepts and techniques developed by means of a running example. This paper was presented at the Social Software conference in May 2004, Copenhagen, organised by PHILOG. We thank the organisers for providing the opportunity, and the participants for their useful feedback.     

Temporal order judgment reveals how number magnitude affects visuospatial attention

The existence of spatial components in the mental representation of number magnitude has raised the question regarding the relation between numbers and spatial attention. We present six experiments in which this relation was examined using a temporal order judgment task to index attentional allocation. Results demonstrate that one important consequence of numerical processing is the automatic allocation of spatial attention, which in turn affects the perception of the temporal order of visual events. Given equal onset time, left-side stimuli are perceived to occur before right-side stimuli when a small number (1, 2) is processed, whereas right-side stimuli are perceived to occur before left-side stimuli when a larger number (8, 9) is processed. In addition, we show that this attentional effect is specific to quantity processing and does not generalize to non-numerical ordinal sequences.     

Temporal distance and ease of retrieval

Construal Level Theory (CLT; Trope & Liberman, 2003) proposes that pro-arguments (pros) constitute high-level construals and counter-arguments (cons) low-level construals. Therefore, pros are more salient for distant-future actions than are cons and the reverse holds for near-future actions (Eyal, Liberman, Trope, & Walther, 2004). We further predicted and results from one experiment show that participants found it easier to generate pros if an action pertained to the distant rather than the near future. For cons the effect was reversed: participants found it more difficult to generate cons if the action pertained to the distant rather than the near future. Consequently, people were more in favor of the action if it pertained to the distant rather than the near future. Ease of retrieval mediated the effect of temporal distance on attitudes. The mutual relevance of the CLT framework and research on ease of retrieval is discussed.     

Neural responses to morphological, syntactic, and semantic properties of single words: an fMRI study

Dissociations in the recognition of specific classes of words have been documented in brain-injured populations. These include deficits in the recognition and production of morphologically complex words as well as impairments specific to particular syntactic classes such as verbs. However, functional imaging evidence for distinctions among the neural systems underlying these dissociations has been inconclusive. We explored the neural systems involved in processing different word classes in a functional Magnetic Resonance Imaging study, contrasting four groups of words co-varying morphological complexity (simple, monomorphemic words vs complex derived or inflected words) and syntactic class (verbs vs nouns/adjectives). Subtraction of word from letter string processing showed activation in left frontal and temporal lobe regions consistent with prior studies of visual word processing. No differences were observed for morphologically complex and simple words, despite adequate power to detect stimulus specific effects. A region of posterior left middle temporal gyrus showed significantly increased activation for verbs. Post hoc analyses showed that this elevated activation could also be related to semantic properties of the stimulus items (verbs have stronger action associations than nouns, and action association is correlated with activation). Results suggest that semantic as well as syntactic factors should be considered when assessing the neural systems involved in single word comprehension.     

Auditory attention to frequency and time: an analogy to visual local-global stimuli

Two priming experiments demonstrated exogenous attentional persistence to the fundamental auditory dimensions of frequency (Experiment 1) and time (Experiment 2). In a divided-attention task, participants responded to an independent dimension, the identification of three-tone sequence patterns, for both prime and probe stimuli. The stimuli were specifically designed to parallel the local-global hierarchical letter stimuli of [Navon D. (1977). Forest before trees: The precedence of global features in visual perception. Cognitive Psychology, 9, 353-383] and the task was designed to parallel subsequent work in visual attention using Navon stimuli [Robertson, L. C. (1996). Attentional persistence for features of hierarchical patterns. Journal of Experimental Psychology: General, 125, 227-249; Ward, L. M. (1982). Determinants of attention to local and global features of visual forms. Journal of Experimental Psychology: Human Perception and Performance, 8, 562-581]. The results are discussed in terms of previous work in auditory attention and previous approaches to auditory local-global processing.     

Auditory backward masking deficits in children with reading disabilities

Studies evaluating temporal auditory processing among individuals with reading and other language deficits have yielded inconsistent findings due to methodological problems () and sample differences. In the current study, seven auditory masking thresholds were measured in fifty-two 7- to 10-year-old children (26 diagnosed with reading disability [RD], 26 without reading disability). Hierarchic multiple regression analyses indicated that RD status predicted performance only in the backward-bandpass noise (p<.05) and backward notched-noise conditions (p<.05), suggesting both temporal and spectral auditory processing deficits. These results suggest that any auditory deficit associated with RD may be more complex than previously hypothesized.