Inhibition of return with rapid serial shifts of attention: implications for memory and visual search

Horowitz and Wolfe (2001) suggested that inhibition of return (IOR) should not be observed in tasks that involve rapid deployments of attention. To examine this issue, five of six possible locations were sequentially cued with either short-duration peripheral cues (50 msec) or long-duration peripheral cues (500 msec). As was expected, IOR was observed in the first two experiments at every cued location with the long-duration cues, with the magnitude of IOR decreasing for earlier cued locations relative to later cued locations. In the short-cue condition, IOR was observed at only one cued location (the second to last). The pattern of results for the short-duration cues was found regardless of whether the fixation cue was of a short (Experiment 1) or a long (Experiment 2) duration. In Experiment 3, the final fixation cue was removed, and IOR was again observed at virtually all locations in both the short- and the long-cue conditions. These findings indicate that IOR can be observed at multiple locations when attention is shifted rapidly between locations.     

Discrimination and differentiation of response number in stimulus directed pecking of pigeons.

In Experiment 1, autoshaping trials terminated with food only if pigeons emitted more than a target number of responses during a trial in one condition and fewer than a target number in another. The median number of responses per trial shifted in accordance wtih the requirements. The responding of yoked-control birds that received response-independent reinforcers did not vary with the response requirements. In Experiment 2, the number of responses in autoshaping trial became the discriminative stimulus for reinforcement in the second component of a chained schedule. In one condition, responding was reinforced only if the number of responses in the first component was above a target value; in the other condition, responding was reinforced only if the number was below the target value. The distribution of the first-component response numbers did not shift systematically between discrimination conditions, but response rates in the second component indicated that the number of responses in the autoshaping trial was a discriminable property behavior.     

Rapid onset and long-term inhibition of return in the multiple cuing paradigm

Inhibition of return (IOR) refers to the finding that targets at cued locations are responded to more slowly than targets at uncued locations when a relatively long temporal interval occurs between the two events. In studies which have examined the time course of IOR (e.g., Samuel & Kat in Psychonomic Bulletin & Review, 10, 897-906, 2003), the effect is generally shown to develop at around 200 ms and dissipate at around 3,000 ms following a cue. A number of recent studies, however, have demonstrated that IOR can develop much more quickly (up to 50 ms following a cue) and last much longer (up to 13 min following a cue) in certain tasks. The present study uses the multiple cuing paradigm to determine whether IOR can be observed outside the normally reported temporal boundaries (300-3,000 ms) when attention is shifted very quickly (every 15 ms) or very slowly (every 1,500 ms) throughout the visual field. IOR was observed as quickly as 30 ms following cue onset and as long as 6,000 ms following cue onset. Implications for the role of IOR in visual search are discussed.     

Attentional SNARC: there's something special about numbers (let us count the ways)

We report a study that examines whether the presentation of irrelevant, ordinal information at central fixation interacts with the allocation of attention beyond fixation. Previous research has demonstrated that number perception influences the allocation of spatial attention, such that the presentation of a spatially nonpredictive number at fixation results in attention being allocated to the left when the central number is low (e.g., 1), and attention being allocated to the right when the central number is high (e.g., 9). Here, we examine whether this attentional SNARC effect (spatial numerical association of response codes) generalizes to other ordinal sequences: letters, days, and months. Though we replicate the attentional SNARC we find that this effect is number-specific, unless participants are required to process the cue in an order-relevant fashion. This discovery of number-specificity has important implications both for the functional separation between SNARC and attention-SNARC effects, as well as lending support to recent theories regarding the specificity of a shared neural architecture between numbers and visuospatial attention.     

Discrimination of response-reinforcer and response-stimulus contingencies in pigeons

For three pigeons (Experiment 1), the presentation of a red response key ended with a food presentation either following two responses separated by at least 10 seconds (a DRL contingency) or following a 10-second response-free period (a DRO contingency). For three other birds (Experiment 2), a brief stimulus presentation terminated the DRL and DRO contingencies. A white side key was presented next and ended with response-dependent food following one contingency and a timeout following the other. Since the contingency on the red key was unsignaled, differential responding on the white side key could indicate that the two response-reinforcer relations had been discriminated. In Experiment 1, the red-key duration and number of responses influenced white-key responding following the contingency that predicted the timeout. A response-initiated DRO was instated, and the influence of red-key duration and response number on white-key responding was diminished. In both experiments, the 10-second time criterion in both contingencies was varied from 0.34 second to 10 seconds. Even at short time intervals the DRO and DRL contingencies were readily discriminated. Pigeons tended to class the two contingencies according to a rule that did not involve simply stimulus duration, numbers of responses, or even the time between a response and its consequence.     

性别、幼儿园教育和英语学习对普通话儿童语音习得的影响

1　引言在研究儿童语言习得过程中 ,人们发现虽然所有正常发展的儿童最终都能习得目标语 ,但是习得的速度有快有慢。性别、家庭的社会经济地位 (包括父亲和母亲的文化程度、职业等 )、兄弟姐妹中的排行、智力、性格、思维方式等社会和个人因素都会对语言习得的速度产生一定的作用。Ｒｉｔｔｅｒｍａｎ＆Ｒｉｃｈｔｎｅｒ( 1 979)和Ｍｏｗｒｅｒ＆Ｂｕｒｇｅｒ( 1 991 )分别比较了男孩和女孩在英语习得过程中发音的音位数目和出现音位错误的数量 ,两项实验均没有发现男孩和女孩在习得语音过程中有显著差异。另有两项早期研究发现语音习得过程…