Isabel Arend

Task-irrelevant visual motion and flicker attenuate the attentional blink

Our reduced ability to correctly report two sequentially presented targets is seen in the robust effect known as the attentional blink (AB; Raymond, Shapiro, & Arnell, 1992). One recent report (Olivers & Nieuwenhuis, 2005) strikingly reveals the AB to be virtually abolished when non-task-demanding music occurs in the background. The authors suggest that a diffuse attentional state is the mediating factor. Here, we seek to broaden the finding’s generality by determining if task-irrelevant visual motion and flicker also attenuate the AB. In our experiments, the AB task was presented together with a background field of moving dots that could moveaway from ortoward the central AB task, or flicker. In the control condition, the dots remained static. The AB was attenuated—though to different degrees—in all experimental conditions, but not in the static condition. Our findings add to the generality of the previous conclusions, and we emphasize an account based on the overallocation of attention.

Emotion recognition following human pulvinar damage

Pulvinar activation has been observed while viewing fearful expressions, but the necessity of this activation to their recognition has not been previously assessed. We measured the processing of emotional facial expressions in a rare patient with complete unilateral loss of the pulvinar. With brief presentations, patient CJ was incapable of recognizing fearful expressions in his contralesional field. Three other patients, with damage limited to the anterior and to the lateral pulvinar, showed no deficits in recognition. In conjunction with anatomical studies of the monkey pulvinar, these results suggest that fear recognition is mediated by the human medial pulvinar. We outline the possible role of the pulvinar in fear recognition, considering both the pulvinars direct and indirect cortical connections with the amygdala, and we suggest that the integrative role of the pulvinar may be primary. Our results suggest that the cortex in isolation from the entire pulvinar is incapable of recognizing fearful expressions.

Spatial and temporal deficits are regionally dissociable in patients with pulvinar lesions

The pulvinar is an important structure for visual attention function. Spatial and temporal attention was examined in three patients with varying pulvinar lesions. Spatial and temporal deficits were dissociable. The patient with anterior damage showed strong spatial but not temporal attention deficits, while the patient with posterior damage showed clear temporal attention deficits, but much reduced spatial problems. A third patient with intermediate damage showed intermediate behaviours. These findings are discussed within the scope of models of visual attention in which the pulvinar facilitates communication between different brain areas: depending upon the specifics of pulvinar damage, communication with different cortical areas may be degraded, thereby producing distinct patterns of deficit.

The role of the human pulvinar in visual attention and action: evidence from temporal-order judgment, saccade decision, and antisaccade tasks.

The pulvinar nucleus of the thalamus has been considered as a key structure for visual attention functions (Grieve, K.L. et al. (2000). Trends Neurosci., 23: 35-39; Shipp, S. (2003). Philos. Trans. R. Soc. Lond. B Biol. Sci., 358(1438): 1605-1624). During the past several years, we have studied the role of the human pulvinar in visual attention and oculomotor behaviour by testing a small group of patients with unilateral pulvinar lesions. Here we summarize some of these findings, and present new evidence for the role of this structure in both eye movements and visual attention through two versions of a temporal-order judgment task and an antisaccade task. Pulvinar damage induces an ipsilesional bias in perceptual temporal-order judgments and in saccadic decision, and also increases the latency of antisaccades away from contralesional targets. The demonstration that pulvinar damage affects both attention and oculomotor behaviour highlights the role of this structure in the integration of visual and oculomotor signals and, more generally, its role in flexibly linking visual stimuli with context-specific motor responses.

SEX DIFFERENCES IN VERBAL REASONING ARE MEDIATED BY SEX DIFFERENCES IN SPATIAL ABILITY

Several meta-analyses have shown that males outperform females in overall spatial ability, while females outperform males in some verbal ability tests, but not in others. The present article measures sex differences in two computerized tests, one thought to reflect verbal reasoning and one thought to reflect dynamic spatial performance. The sample comprised 1,593 university graduates (794 females and 799 males). Results show that males outperform females in both tests. However, sex differences in verbal reasoning turn to be nonsignificant when sex differences in dynamic spatial performance are statistically removed. The finding is interpreted from the previously demonstrated fact that the verbal reasoning test requires spatial processing. The result raises doubts about the common practice of evaluating sex differences in cognitive abilities from the tests’ superficial characteristics or information content. The interpretation of the observed findings strongly requires the analysis of the tests’ cognitive requirements.

Perceived health from biological motion predicts voting behaviour

Body motion signals socially relevant traits like the sex, age, and even the genetic quality of actors and may therefore facilitate various social judgements. By examining ratings and voting decisions based solely on body motion of political candidates, we considered how the candidates’ motion affected peoples judgements and voting behaviour. In two experiments, participants viewed stick figure motion displays made from videos of politicians in public debate. Participants rated the motion displays for a variety of social traits and then indicated their vote preference. In both experiments, perceived physical health was the single best predictor of vote choice, and no two-factor model produced significant improvement. Notably, although attractiveness and leadership correlated with voting behaviour, neither provided additional explanatory power to a single-factor model of health alone. Our results demonstrate for the first time that motion can produce systematic vote preferences.

Quantifying cognitive complexity: evidence from a reasoning task

There are some doubts about the nature of cognitive complexity. It has been proposed that the loadings on the first un-rotated factor can be taken as a way to quantify the cognitive complexity of a given task. However, the evidence is sparse. The present study tests 1968 participants in a computerized task that comprises linear syllogisms or three-term series problems. The correlation matrix is submitted to a factor analysis. The first un-rotated factor is taken as the vector of cognitive complexity. The vector of task difficulty was obtained after the proportion of participants that failed each syllogism. In addition to task empirical difficulty, three information processing models are taken as predictors of cognitive complexity. Then, regression analyses were carried out to predict cognitive complexity from the information processing (IP) models and task difficulty. Results show that the IP models and task difficulty predict cognitive complexity defined by the loadings on the first un-rotated factor. Therefore, it is concluded that those loadings can be taken as a way to quantify cognitive complexity.

Dissociating emotion and attention functions in the pulvinar nucleus of the thalamus.

OBJECTIVES Recent models on emotional processing consider a major role for the pulvinar in the coordination of emotion processing; however, these models do not specify the type of cognitive mechanisms that the pulvinar may be subserving during emotional processing. In this opinion paper, we focus on the role of the different pulvinar subdivisions in emotion and attention. First, we review a number of neuropsychology studies and recent models that indicate that the medial nucleus of the pulvinar is critical for intact emotional processing. Then, we suggest that the role of the medial pulvinar in emotional processing is binding emotionally relevant features during working memory updating. METHOD We carefully examined reports that describe different cognitive impairments following lesions to different pulvinar subdivisions. RESULTS By linking these detailed neuropsychology reports to recent neuroimaging findings, we show that lesions to specific parts of the pulvinar can dramatically affect attentional processes while leaving emotion processing spared. CONCLUSIONS We suggest a comprehensive model that specifies the functional role of the different pulvinar subdivisions in emotion-attention interplay. We propose that the impairments in emotional processing following lesions to the medial pulvinar may be related to the role of this nucleus in emotionally relevant working memory updating. The aim of this model is to foster future research examining specific functions along the different anatomical pulvinar subdivisions.

Oculomotor integration in patients with a pulvinar lesion

The pulvinar nucleus of the thalamus, with its connections to visual areas and to frontal and parietal oculomotor cortex, might serve as a nexus for integrating cortical control of voluntary eye movements with reflexive eye movements generated by the superior colliculus. To investigate this hypothesis, we tested five patients with a unilateral lesion of the pulvinar on the oculomotor capture paradigm. In this task, participants have to ignore a distractor item and make a saccade to a target in a visual search display. Results showed that the interference of the distractor was stronger when it was presented contralateral to their lesion compared to when it was presented in the ipsilesional visual field. These findings were confirmed by an additional single case experiment in which we measured saccade trajectory deviations as evoked by a single distractor. These results show that the pulvinar is involved in the successful influence of higher order signals (like our goals and intentions) on the guidance of our eye movements.

A Betting Dice Test to Study the Interactive Style of Risk-Taking Behavior

The purpose of this research was to assess the consistency and stability of risk-behavior within the interactive style perspective through a betting dice test (Ribes & Sánchez, 1992). We used two different versions of the betting dice test (BDT), in which some parametric values were changed in order to verify the interactive style configuration. When BDT version 1 was used (Study 1) we found that, even though the response options had the same expected value, subjects presented a conservative strategy, and that the behavior remained stable after 2 hr. The second BDT version (Study 2) allowed us to verify two aspects of the risk-taking behavior: (a) Subjects’ risk behavior remains stable after 1 yr; and (b) the assumed risk varies between the two versions of the BDT. These results are discussed within the interactive style framework.