Are spatial selection and identity extraction separable when attention is controlled endogenously?

Visual search for a target involves two processes: spatial selection and identity extraction. Ghorashi, Enns, and Di Lollo (2008) found these processes to be independent and surmised that they were carried out along distinct visual pathways: dorsal and ventral, respectively. The two experiments that are described in the present article evaluated this hypothesis. Attentional-blink methodology was combined with voluntary spatial cuing in a visual search task: Intertarget lag was used to manipulate identity extraction; predictive cues were used to signal target locations. Central digit cues in Experiment 1 required participants to identify digits before voluntarily directing attention to a corresponding location, whereas flashed dots in Experiment 2 (indicating an opposite location) required attentional redeployment without prior cue identification. Consistent with the dual-pathway hypothesis, cuing was impaired only when the first target and the number cue competed for ventral-pathway mechanisms. Collectively, the results support the dual-pathway account of the separability of spatial selection and identity extraction.     

Temporal information coding properties of a network of inhibitory interneurons

Inhibitory interneurons are coupled by electrical and inhibitory synapses and exert a powerful control of the discharges of principal cells. In this paper, the transmission properties of excitatory synaptic inputs by a network of interneurons, are studied by using a computational approach. It is shown that both the rise and decay time constants, describing the time course of the excitatory synaptic inputs, have a strong effect on the output jitter of the fired spikes. Similar results were found by changing the values of the other parameters describing the network. Lastly, it is shown that the presence of the electrical coupling between interneurons confers to the network the capability of transmitting, with less temporal spread, the timing information contained in its inputs.     

从词频和新旧效应探讨再认测验中的定向遗忘

本文采用字表方式,从高低词频和新旧效应角度,探讨内隐和外显测验中定向遗忘效应的存在性及其机制问题。结果发现:(1)低频词在两种测验中都存在定向遗忘效应,而高频词仅存在于外显测验中。(2)两种测验中都存在指示记住的新旧效应,而外显测验中不存在指示忘记的新旧效应。由此推断,测验间在没有"意识和无意识"相互污染的理想情况下,只有外显测验可获得定向遗忘效应;定向遗忘的机制可能是选择性编码机制。     

Visual search is postponed during the attentional blink until the system is suitably reconfigured

J. S. Joseph, M. M. Chun, and K. Nakayama (1997) found that pop-out visual search was impaired as a function of intertarget lag in an attentional blink (AB) paradigm in which the 1st target was a letter and the 2nd target was a search display. In 4 experiments, the present authors tested the implication that search efficiency should be similarly impaired (steeper search slopes at shorter lags). A conventional AB deficit was found, but, contrary to expectations, search slopes were invariant with lag. These results suggest that no search can be carried out during the period of the AB. Instead, the search is postponed until after the 1st target has been processed. The authors conclude that efficient visual search cannot be carried out unless the visual system is configured appropriately for the search task. If the initial configuration is inappropriate, processing of the 2nd target is held in abeyance until the system has been suitably reconfigured.     

爬行经验与婴儿空间认知能力的发展

本研究采用“A非B”时间延搁测验对34名9-12个月缨儿的爬行经验与其空间认知能力发展的关系进行了研究。协方差分析表明,婴儿的爬行经验对其在“A非B”延搁任务中表现出来的空间认知能力有显著的主效应,而年龄的效应不明显;进一步分析显示,爬行经验7周以内的婴儿与爬行经验10周以上的婴儿空间认知能力发展水平差异显著。本研究说明,爬行经验与婴儿在“A非B”延搁任务上表现出来的空间认知能力发展有密切的关系。     

Effect of physical stimulation on motor inhibition in children

The effect of physical stimulation on motor inhibition and cognitive performance of 70 third-grade children was examined. 46 subjects participated in a brief, but strenuous obstacle course. Their performance on two motor inhibition tasks, a short-term memory/attentional task, and a test assessing reflectivity was assessed before the stimulation, immediately afterward, and again after a 30-min. delay. A control group (n = 24) received comparable experience without the physical intervention. Physical stimulation facilitated fine motor inhibition at both the immediate and delayed retest. The intervention interfered with an apparent practice effect on the attentional task. No condition effects were noted for gross motor performance or reflectivity, although girls were significantly more reflective at retest. It is proposed that physical stimulation augments certain aspects of inhibitory control in children.     

Differences in reported symptom profile between panic disorder and other DSM-III-R anxiety disorders.

Previous research has indicated that reports of panic attacks are associated with a different set of symptoms to reports of generalized anxiety. The present two studies attempted to extend these findings to specific (situational) fears. In Study 1, 55 subjects with panic disorder were compared on their symptom profile during their panic attacks to 65 subjects with other anxiety disorders [simple phobia, social phobia and obsessive-compulsive disorder (OCD)] during response to their feared cue. The results indicated that, compared to subjects with other anxiety disorders, subjects with panic disorder were more likely to report parasthesias, dizziness, faintness, unreality, dyspnea, fear of dying and fear of going crazy/losing control. In Study 2, 90 subjects meeting diagnostic criteria for both panic disorder and another anxiety disorder (simple phobia, social phobia or OCD) were compared on the symptoms experienced during their unexpected panic attacks and their situationally-triggered fears respectively. Combining the symptoms found in Study 1 to differ between the groups into a linear combination, there was a significant interaction found between the type of fear reaction (panic attack vs cued fear response) and symptom group. Taken together, these findings suggest that reports of unexpected panic attacks associated with panic disorder are characterized by a different symptom profile to reports of specific fear reactions that are part of a phobic disorder or OCD.