Inhibition of return and object-based attentional selection.

Visual attention research has revealed that attentional allocation can occur in space- and/or object-based coordinates. Using the direct and elegant design of R. Egly, J. Driver, and R. Rafal (1994), the present experiments tested whether space- and object-based inhibition of return (IOR) emerge under similar time courses. The experiments were capable of isolating both space- and object-based effects induced by peripheral and back-to-center cues. The results generally support the contention that spatially nonpredictive cues are effective in producing space-based IOR at a variety of stimulus onset asynchronies (SOAs) and under a variety of stimulus conditions. Whether facilitatory or inhibitory in direction, the object-based effects occurred over a very different time course than did the space-based effects. Reliable object-based IOR was only found under limited conditions and was tied to the time since the most recent cue (peripheral or central). The finding that object-based effects are generally determined by SOA from the most recent cue may help to resolve discrepancies in the IOR literature. These findings also have implications for the search facilitator role that IOR is purported to play in the guidance of visual attention. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The negative compatibility effect: Unconscious inhibition influences reaction time and response selection.

In the negative compatibility effect (NCE) a masked prime arrow, pointing left or right, is followed by an unmasked (visible) target arrow. The task is to press the left or right switch corresponding to the visible arrow. Surprisingly, reaction time is longer (slowed) when the prime and target indicate the same, rather than different, responses. By contrast, the effect of an unmasked prime is positive- opposite to the NCE. This indicates that the NCE is not attributable to incomplete masking; to the extent that the prime is visible, the NCE would be reduced by this positive influence. Thus, the NCE appears to result from unconscious processing of the prime and, in that sense, may be a form of subliminal perception. Additional findings show that the NCE is due to inhibition of a response code, that it is automatic in that it occurs even if the information in the prime and target could be ignored, and that it also influences response selection. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Triazolam impairs inhibitory control of behavior in humans.

This study tested the effects of the sedative-hypnotic drug triazolam (Halcion) on the ability to inhibit behavior in humans. Thirty adults practiced a stop-signal task that measured their ability to inhibit and activate behavioral responses on a choice reaction time task. Equal numbers of participants (i.e., n?=?10) then received either 0.25 mg, 0.125 mg, or 0 mg (placebo) of triazolam under double-blind conditions and performed the task intermittently over a 3-hr period. In accord with the hypothesis, triazolam reduced response inhibitions and increased the time required to inhibit a response. The drug also slowed the activation of responses. The findings contribute to the understanding of the basic behavioral mechanisms by which sedative-hypnotic drugs can produce states of behavioral disinhibition in some individuals. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Attentional momentum does not underlie the inhibition of return effect.

J. Pratt, T. M. Spalek, and F. Bradshaw (1999) recently proposed that attentional momentum is the mechanism underlying the inhibition of return (IOR) effect. They suggested that momentum associated with an attentional movement away from a peripherally cued location and toward an uncued opposite location is essential and fundamental to the finding of an IOR effect. Although it is clear from the present study and from a reanalysis of data from Pratt et al. that response time can be facilitated at an uncued opposite location, this putative effect of attentional momentum is neither robust nor reliable. First, it occurs for only a minority of participants. Second, it occurs in only a subset of the cued display positions. And finally, it is uncorrelated with the occurrence of IOR. Together the data indicate that the attentional momentum hypothesis is an overgeneralization and that it does not underlie the robust and reliable IOR effect. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of contextual similarity and target-repetition proportion on negative priming in RT distributional analyses.

Participants' reaction time (RT) data in a prime-probe flanker task (e.g., ABA–CAC) were analyzed in terms of the characteristics of RT distribution to examine possible mechanisms that produce negative priming. When the prime and probe were presented in the same context and the proportion of repetition-target trials (TRP) was 0.33, negative priming increased as a function of RT bins, supporting the episodic retrieval account (Neill, 1997). Manipulations that discourage the use of episodic retrieval (i.e., switching context between prime and probe or 0.00 TRP) eliminated the increase in negative priming across RT bins, even though the overall effect remained significant. These data support a dual-mechanism account in which, depending on task demands, both selective inhibition and episodic retrieval can be involved in producing negative priming. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Aging and emotional memory: Cognitive mechanisms underlying the positivity effect.

Younger adults tend to remember negative information better than positive or neutral information (negativity bias). The negativity bias is reduced in aging, with older adults occasionally exhibiting superior memory for positive, as opposed to negative or neutral, information (positivity bias). Two experiments with younger (N = 24 in Experiment 1, N = 25 in Experiment 2; age range: 18?35 years) and older adults (N = 24 in both experiments; age range: 60?85 years) investigated the cognitive mechanisms responsible for age-related differences in recognition memory for emotional information. Results from diffusion model analyses (R. Ratcliff, 1978) indicated that the effects of valence on response bias were similar in both age groups but that Age × Valence interactions emerged in memory retrieval. Specifically, older adults experienced greater overall familiarity for positive items than younger adults. We interpret this finding in terms of an age-related increase in the accessibility of positive information in long-term memory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Strategic effects in word naming: Examining the route-emphasis versus time-criterion accounts.

K. Rastle and M. Coltheart (1999) demonstrated that both nonwords and low-frequency regular words are named more slowly when mixed with first-phoneme irregular word fillers (e.g., CHEF) than when mixed with third-phoneme irregular word fillers (e.g., GLOW). Those authors suggested that their effects were due to a strategic de-emphasis of the nonlexical route when first-phoneme irregular fillers were used. An alternative explanation is that these results simply reflect a more lax position of a time criterion (S. J. Lupker, P. Brown, and L. Colombo, 1997) in the first-phoneme irregular filler condition. We contrasted these 2 accounts in 4 experiments. In all experiments, target naming latencies were longer when the fillers were harder to name, regardless of whether the fillers were nonwords or exception words. These results strongly favor a time-criterion account of K. Rastle and M. Coltheart's effects. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Simon effect with and without awareness of the accessory stimulus.

The authors investigated whether a Simon effect could be observed in an accessory-stimulus Simon task when participants were unaware of the task-irrelevant accessory cue. In Experiment 1A a central visual target was accompanied by a suprathreshold visual lateral cue. A regular Simon effect (i.e., faster cue-response corresponding reaction times [RTs]) was found. Experiment 1B demonstrated that this effect cannot be attributed to perceptual grouping of the target and cue. Experiments 2A, 2B, and 2C showed a reverse Simon effect (i.e., faster noncorresponding RTs) when participants were not aware of the cue. In this condition, the Simon effect would occur relative to the reorientation of attention from the cue, which would initially capture attention, toward the target. This conclusion is supported by the results of Experiments 3A and 3B, in which the reorientation of attention was induced by having the target flash after its onset. With suprathreshold cues either a reverse or regular Simon effect was observed by using a 100-ms or ≥200-ms onset flashing interval, respectively, whereas with subthreshold cues a reverse Simon effect was found irrespective of the interval length. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Brief glimpses of the brain.

Reviews the book, Reaction Times, edited by A. T. Welford (1981). The combination of title, author, and publisher suggest a powerful psychological study of reaction time. Yet the content of the book is not a grand analysis of reaction time but rather a compendium of unevenly written chapters about response time contributed by Welford and seven of his Australian colleagues with a heavy concentration on their own work. The book lacks quantitative presentations and often misrepresents quantitative theories. The extent of these misrepresentations is sufficiently large to make sections of the book unsuited to student instruction. Yet the volume's flaws may prove to be a blessing in disguise if the contributors seize this opportunity to make major revisions that lead towards a vastly improved second edition. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The role of response selection for inhibition of task sets in task shifting.

Response selection in task shifting was explored using a go/no-go methodology. The no-go signal occurred unpredictably with stimulus onset so that all trials required task preparation but only go trials required response selection. Experiment 1 showed that shift costs were absent after no-go trials, indicating that response processes are crucial for shift costs. In Experiment 2, backward inhibition was absent after no-go trials. Experiments 3 and 4 demonstrated that response selection, rather than execution, causes backward inhibition. All 4 experiments showed effects of preparation time in go trials, suggesting that advance preparation must have also occurred in no-go trials. The authors concluded that inhibition of irrelevant task sets arises only at response selection and that residual shift costs reflect such persisting inhibition. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of double stimulation: Temporary inhibition of response.

This paper deals primarily with findings in the area of reaction time, with a lesser focus on dichotic listening studies and stereoscopic perception. The generality of a temporary inhibition of response (TIR) phenomenon, given double stimulation in close temporal contiguity, is posited. 3 alternatives are offered: an S-centered (information and/or "filter" theory), an O-centered (the "expectancy" position), and an R-centered (a competing-response position) explanation. The latter is suggested as most adequately dealing with the data, although the alternatives are not seen as mutually exclusive. A method for the training of prepotent responses is suggested, along with an associated line of research into the TIR phenomenon. (38 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Fusion prevents the redundant signals effect: Evidence from stereoscopically presented stimuli.

In a simple reaction time (RT) experiment, visual stimuli were stereoscopically presented either to one eye (single stimulation) or to both eyes (redundant stimulation), with brightness matched for single and redundant stimulations. Redundant stimulation resulted in two separate percepts when noncorresponding retinal areas were stimulated, whereas it resulted in a single fused percept when corresponding areas were stimulated. With stimulation of noncorresponding areas, mean RT was shorter to redundant than to single stimulation, replicating the redundant signals effect (RSE) commonly found with visual stimuli. With stimulation of corresponding areas, however, no RSE was observed. This suggests that the RSE is driven by the number of percepts rather than by the number of stimulated receptors or sensory organs. These results are consistent with previous findings in the auditory modality and have implications for models of the RSE. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Inhibitory Control in Rats Performing a Stop-Signal Reaction-Time Task: Effects of Lesions of the Medial Striatum and d-Amphetamine.

The stop-signal task measures the ability to inhibit a response that has already been initiated, that is, the ability to stop. Imaging studies have implicated frontostriatal circuitry in the mediation of this form of response control. The authors report inhibition functions of normal rats and those with medial striatal damage performing the stop-signal task. Excitotoxic lesions of the medial striatum produced significant deficits on task performance, including increased omissions on the go task and flattened inhibition function, possibly as a result of increased reaction-time mean and variability. Medial striatal lesions also significantly slowed stop-signal reaction time. Subsequent treatment with d-amphetamine removed (0.3 mg/kg) or exacerbated (1.0 mg/kg) this deficit. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effect of aversive stimuli on reaction time in schizophrenia.

"… the experiment was to assess the motivational role of aversive stimuli in modifying the performance of normal and… schizophrenic… males… [on] a visual reaction time task… . During… [one] series Ss responded under… experimental conditions… [part of which] involved the use of intense noise as an aversive stimulus. None of the experimental conditions appreciably altered the performance of normal Ss. However, schizophrenic Ss performing under… [conditions involving noise] displayed greater improvement than control Ss." 22 refs. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The concept of task versus person orientation in nursing.

To clarify the concept of task versus person orientation in nursing, a factor analysis of 24 personality-and nursing-attitude variables was performed on 160 nurses from long- and short-term treatment settings in psychiatry and general medicine. 3 factors, Leadership Skills, Hostile-Self-Seeking, and Dependent-Exploited sampled behaviors in the interpersonal sphere and particularly traits related to leadership capability. The 4th factor, Impersonal-Orderly, contained many characteristics of the "Authoritarian Personality." An emphasis on the skilled technical aspects of nursing was one of the elements in this factor. In general, the derived factor scores effectively differentiated nurses from the treatment settings in this study. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Reaction time in the cold.

"Visual RT's were elicited from 620 soldiers sorted into 14 different groups representing a variety of ambient temperatures, windspeeds and windchills… . 1. At low windspeed… low ambient temperature has no effect on RS… . [reciprocal of RT]. 2. At windspeeds of 10 mph and greater, low ambient temperature produces a significant decrease in RA. 3. Windspeed produces a significant decrease in RS. 4. Mild exercise produces a small recover in RS. 5. If men of low 'physiological cold tolerance' are removed from the more severe environmental conditions and if Ss wear protective clothing, RS is essentially a linear decreasing function of windchill." (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Inhibition of ongoing responses following frontal, nonfrontal, and basal ganglia lesions.

The authors investigated the role of the frontal lobes and the basal ganglia in the inhibition of ongoing responses. Seventeen patients with frontal lesions (FG), 20 patients with lesions outside the frontal cortex (NFG), 8 patients with lesions to the basal ganglia (BG), and 20 orthopedic controls (OG) performed the stop-signal task that allows the estimation of the time it takes to inhibit an ongoing reaction (stop signal reaction time [SSRT]). The FG and the BG showed significantly longer SSRTs than the OG. Within the FG, patients with right and bilateral lesions showed significantly longer SSRTs than patients with left lesions. Results provide evidence for a role of the frontal lobes and the basal ganglia in the inhibition of ongoing responses. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Automatic and intentional activation of task sets.

Four experiments examined automatic and intentional activation of task sets in a switching paradigm. Experiment 1 demonstrated incidental task sequence learning that was not accompanied by verbalizable task sequence knowledge. This learning did not affect task shift cost and may be attributed to automatic task-set activation. In Experiment 2, both shift cost and learning effect increased when the response–cue interval was short, indicating the influence of residual, persisting activation of the preceding task set. In Experiment 3, learning disappeared with a long cue–stimulus interval (CSI), which resulted in a strong preparation effect. This preparation, however, reduced reaction time level but was not specific to task shifts. Finally, experiment 4 showed that a within-subject CSI variation also leads to reduced shift costs. Together, the data suggest an activational account of task preparation and may have relevant implications for inhibitory accounts. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Auditory S-R compatibility: The effect of an irrelevant cue on information processing.

Two experiments demonstrated the existence of a strong population stereotype which affected the processing of verbal commands. In a choice RT task, Ss pressed the right- or left-hand key in response to the words "right" or "left" which were presented to the right or left ear. RT was significantly faster when the content of the command corresponded to the ear stimulated than when it did not, i.e., information processing was affected by a cue irrelevant to the task itself, the ear in which the command was heard. Removing S's uncertainty regarding the ear to be stimulated resulted in significantly faster RT, and reduced but did not eliminate the effect of the irrelevant directional cue. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Inhibition et mémoire de travail : effet d'une privation aigu? de sommeil sur une tache de génération aléatoire.

The literature contains inconsistent data on the effects of acute sleep deprivation on the superior cognitive functions. The primary purpose of this study is to determine the effectiveness of inhibition, one of the functions of the working memory executive centre (EC), over an extended, 36-hour waking period. Inhibition is a cognitive mechanism whereby individuals ignore non-relevant information recorded in their working memory. We also tested the effects of a 36- hour period of acute sleep deprivation on simple reaction time. Twelve young, healthy volunteers (M=21.5 years, ?=2.3) performed a random generation task involving letters and a simple reaction time psychomotor test over four sessions held at 10-hour intervals. Each participant was assigned a "constant routine." Participants were kept awake in a prone position within a room whose environment was held strictly constant (light, noise, temperature, meals, etc.). This control procedure provided assurance that any variation in participant performance was solely caused by sleep deprivation. The random generation task, nearly two minutes in length, consisted in verbally producing a sequence of 100 letters in a random fashion (i.e. by inhibiting, for example, alphabetical order) and by keeping to a set rhythm... (PsycINFO Database Record (c) 2010 APA, all rights reserved)