Inhibition of return for the length of a line?

Inhibition of return is most often measured using an exogenous spatial cuing method. The experiments presented here follow up on a small number of studies that have examined whether a similar effect occurs for nonspatial stimulus attributes. In Experiments 1 and 2, the task was to identify a target line as either short or long. In this context, targets on valid trials were of the same length as that of a preceding cue, whereas targets on invalid trials were of a different length than that of a preceding cue. The results were similar to those in spatial orienting studies in that responses were slower for valid than for invalid targets only at stimulus onset asynchronies (SOAs) longer than 300 msec. In Experiment 3, the stimuli were the same but the task was to detect the onset of the target line. This task change resulted in slower responses for valid than for invalid targets at all SOAs. A similar result was observed in Experiment 4, in which validity was defined by color rather than line length, and the task was to identify the target color. The discussion centers on an opponent process approach to interpreting cuing effects, and consequent difficulties in distinguishing spatial and nonspatial cuing effects based on their time course.     

Inhibition of return: A “depth-blind” mechanism?

When attention is oriented to a peripheral visual event, observers respond faster to stimuli presented at a cued location than at an uncued location. Following initial reaction time facilitation responses are slower to stimuli subsequently displayed at the cued location, an effect known as inhibition of return (IOR). Both facilitatory and inhibitory effects have been extensively investigated in two-dimensional space. Facilitation has also been documented in three-dimensional space, however the presence of IOR in 3D space is unclear, possibly because IOR has not been evaluated in an empty 3D space. Determining if IOR is sensitive to the depth plane of stimuli or if only their bi-dimensional location is inhibited may clarify the nature of the IOR. To address this issue, we used an attentional cueing paradigm in three-dimensional (3D) space. Results were obtained from fourteen participants showed IOR components in 3D space when binocular disparity was used to induce depth. We conclude that attentional orienting in depth operates as efficiently as in the bi-dimensional space.     

Inhibition of return in visual marking? The importance of the interstimulus interval and the type of search task

Four experiments are presented that examine the possibility that inhibition of return (IOR) may occur in visual marking. Previously, Watson and Humphreys (1997), using a cue duration of 750 ms and an interstimulus interval (ISI) of 250 ms, concluded that IOR was not present in visual marking. In the present study, the first experiment examined three ISIs (250 ms, 500 ms, and 750 ms) with a constant stimulus onset asynchrony (SOA, 1000 ms) in a typical cueing paradigm and failed to find IOR with the short ISI. Based on these findings, the second (feature search) and third (conjunction search) experiments tested for IOR by using a visual marking paradigm with a 500 ms ISI. Evidence for IOR was found in the feature search (preview condition similar to half-elements baseline condition) and not in the conjunction search (preview condition similar to the all-elements baseline). The typical preview effect was found in Experiment 4 with a cue duration 1000 ms and no ISI. Overall, these findings indicate that IOR may play a role in visual marking, but only with feature search tasks and long ISIs between displays.     

Is “Inhibition of Return” due to the inhibition of the return of attention?

Inhibition of Return (IOR) is usually explained in terms of orienting–reorienting of attention, emphasizing an underlying mechanism that inhibits the return of attention to previously selected locations. Recent data challenge this explanation to the extent that the IOR effect is observed at the location where attention is oriented to, where no reorienting of attention is needed. To date, these studies have involved endogenous attentional selection of attention and thus indicate a dissociation between the voluntary attention of spatial attention and the IOR effect. The present work demonstrates a dissociation between the involuntary orienting of spatial attention and the IOR effect. We combined nonpredictive peripheral cues with nonpredictive central orienting cues (either arrows or gaze). The IOR effect was observed to operate independent of involuntary spatial orienting. These data speak against the “reorienting hypothesis” of IOR. We suggest an alternative explanation whereby the IOR effect reflects a cost in detecting a new event (the target) at the location where another event (a cue) was coded before.     

Action or attention in social inhibition of return?

Psychological Research - When two individuals alternate reaching responses to targets located in a visual display, reaction times are longer when responses are directed to where the co-actor just...     

Inhibition of return and visual search: how many separate loci are inhibited?

Using a novel sequential visual search paradigm Danziger, Kingstone, and Snyder (1998) demonstrated that inhibition of return (IOR) can reside at three spatial locations. In the present study, we extended the work of Danziger et al. by investigating whether there is a limit to the number of locations that can be inhibited in a sequential visual search task. Our study revealed that IOR can be measured at a minimum of five locations. The magnitude of the IOR effect was largest at the most recently searched location and declined from there in an approximately linear fashion. Two models that can account for our data are presented.     

What is perseverated in schizophrenia? Evidence of abnormal response plasticity in the saccadic system

Although perseveration is sometimes attributed to defective set switching, the authors have recently shown that set-switching is normal in schizophrenia. In this article, the authors tested for persistent states of the saccadic response system, rather than set perseveration. Schizophrenic and healthy subjects performed antisaccades and prosaccades. The authors analyzed for 3 carry-over effects. First, whereas the latency of the current saccade correlated with that of the prior saccade in both groups, the correlations under mixed-task conditions declined in healthy but not in schizophrenic subjects. Second, antisaccades in penultimate trials delayed upcoming saccades in schizophrenic but not in healthy subjects. Third, schizophrenic subjects were more likely to erroneously perseverate the direction of a prior antisaccade but not a prior prosaccade. The authors concluded that, in schizophrenia, the effects of correct antisaccades are persistent not weak. Saccades in schizophrenia are characterized by perseveration of antisaccade-induced changes in the saccadic response system rather than failures to switch task set.     

Does “inhibition of return” occur in discrimination tasks?

When attention is drawn to a location and then withdrawn, responding to a stimulus at that location may be slower than to one at a new location. This “inhibition of return” (IOR) has not been reliably demonstrated in tasks that require discrimination of targets from nontargets. The present experiments replicated IOR in detection and localization tasks only when target/nontarget discrimination was not also required. When discrimination was required, a consistent samelocation advantage occurred for repeated targets. Changed targets may, however, induce a bias toward opposite responses. The results cast doubt on IOR as a general attentional phenomenon.     

How social is social inhibition of return?

A number of studies have shown that the motor actions of one individual can affect the attention of an observer. In one notable example, “social inhibition of return,” observers are relatively slow to initiate a response to a location where another individual has just responded. In the present article we examine the degree to which this phenomenon can be considered a social effect. We find that unlike the related social, or “joint,” Simon effect, social inhibition of return is not influenced by competitive versus cooperative interaction, nor by live versus recorded interaction. We do find however that co-actors need to turn-take in order for the effect to occur. Thus, so-called “social” inhibition of return only reaches a minimal threshold to be considered a social phenomenon.     

A role of goals for social inhibition of return?

The social inhibition of return (sIOR) effect refers to the finding that response initiation times are longer if a movement is executed to a location where another person has responded to just before. Previous studies have examined the influence of the goal of the action on sIOR. In these studies, however, the movement endpoint and to-be-attained goal (e.g., touching/pressing a response key) were at the same spatial location. In the present two experiments, we disentangled movement endpoint and goal's identity and locations by means of introducing action effects that followed directly from a movement. Similar methods were previously shown powerful enough to clearly show the importance of action goals for other phenomena—a finding consistent with effect-based theories of action control, such as the ideomotor theory. The results of the present study revealed that sIOR was shaped by the movement endpoint location, not the goal's identity or location. That is, in both experiments, an sIOR effect was observed, but the magnitude of the sIOR effect was not modulated by repetitions/switches of goals or their locations. Thus, results indicate that goals play a negligible role in the emergence of the sIOR and, consequently, highlight the importance of action observation for the emergence of the sIOR effect.     

Is inhibition of return a reflexive effect?

The inhibition of return (IOR) phenomenon is routinely considered an effect of reflexive attention because the paradigm used to generate IOR employs peripheral cues that are uninformative as to where a target will appear. Because the cues are spatially unreliable it is thought that there is no reason for attention to be committed volitionally to them, and hence, the IOR effect is considered reflexive. What has been generally overlooked, however, is that the cues provide reliable temporal information as to when a target will occur. This predictive information is used by participants to prepare volitionally for when a target is likely to appear. We investigated whether the IOR effect is a product of the volitional application of attention to peripheral cues for the use of their temporal information. To test this idea we rendered the temporal information provided by peripheral cues unreliable. While this eliminated participants using the cues volitionally, it did not abolish the IOR phenomenon. These data demonstrate two new findings. First, the IOR effect is fundamentally a reflexive phenomenon. Second, when peripheral cues are not used volitionally, the IOR effect is attenuated. Together, the present findings indicate that the IOR effect can be modulated by volitional (top-down) processes but it is not the product of them. We argue that an intimate link between fronto-parietal regions and the superior colliculus provide a functional neural mechanism for this volitional effect to impact IOR.     

What determines saccade timing in sequences of coordinated eye and hand movements?

In action sequences, the eyes are generally fixated ahead of the stimulus being responded to, overlapping the processing of adjacent stimuli. What determines when the saccade to the next item is initiated and what processing is overlapped remain controversial. Saccade initiation has been linked directly to the difficulty of the underlying processing on the fixated item or to a rhythmic timer whose period is adjusted to the difficulty of the context. We compared the effects of item and context difficulty when subjects made speeded choice responses to five visual stimuli arrayed linearly. Item difficulty was manipulated by varying stimulus-response compatibility, creating contexts (sequences) whose average item difficulty differed. Results showed that saccade initiation time reflected item difficulty, not context difficulty, with evidence that saccade initiation was delayed until central processing was completed. We discuss the implications of these results for the control of saccades and processing in action sequences.     

Why do gorillas make sequences of gestures?

Great ape gestures have attracted considerable research interest in recent years, prompted by their flexible and intentional pattern of use; but almost all studies have focused on single gestures. Here, we report the first quantitative analysis of sequential gesture use in western gorillas (Gorilla gorilla gorilla), using data from three captive groups and one African study site. We found no evidence that gesture sequences were given for reasons of increased communicative efficiency over single gestures. Longer sequences of repeated gestures did not increase the likelihood of response, and using a sequence was seldom in reaction to communicative failure. Sequential combination of two gestures with similar meanings did not generally increase effectiveness, and sometimes reduced it. Gesture sequences were closely associated with play contexts. Markov transition analysis showed two networks of frequently co-occurring gestures, both consisting of gestures used to regulate play. One network comprised only tactile gestures, the other a mix of silent, audible and tactile gestures; apparently, these clusters resulted from gesture use in play with proximal or distal contact, respectively. No evidence was found for syntactic effects of sequential combination: meanings changed little or not at all. Semantically, many gestures overlapped massively with others in their core information (i.e. message), and gesture messages spanned relatively few functions. We suggest that the underlying semantics of gorilla gestures is highly simplified compared to that of human words. Gesture sequences allow continual adjustment of the tempo and nature of social interactions, rather than generally conveying semantically referential information or syntactic structures.     

Do action goals mediate social inhibition of return?

Social inhibition of return is the phenomenon whereby an individual is slower to reach to locations to which another individual has recently responded. Although this suggests that an observer represents another person's action, little is known about which aspects of the action are encoded. The present work describes a series of three experiments examining whether social inhibition of return represents the endpoint goal of the action, i.e., is 'goal based'. Pairs of participants sat opposite to one another and alternated responses to a cued or non-cued object presented on a table top. Importantly, either the two participants performed the same interaction with the object or a different interaction. Although all our experiments showed social inhibition of return, the size of the effect was not modulated according to whether each participant had the same or different goal. We conclude that although the mechanisms giving rise to social inhibition of return do encode some aspects of a response they do not code for terminal action goals.     

Just Sustainability? Sustainability and Social Justice in Professional Codes of Ethics for Engineers

Should environmental, social, and economic sustainability be of primary concern to engineers? Should social justice be among these concerns? Although the deterioration of our natural environment and the increase in social injustices are among today’s most pressing and important issues, engineering codes of ethics and their paramountcy clause, which contains those values most important to engineering and to what it means to be an engineer, do not yet put either concept on a par with the safety, health, and welfare of the public. This paper addresses a recent proposal by Michelfelder and Jones (2011) to include sustainability in the paramountcy clause as a way of rectifying the current disregard for social justice issues in the engineering codes. That proposal builds on a certain notion of sustainability that includes social justice as one of its dimensions and claims that social justice is a necessary condition for sustainability, not vice versa. The relationship between these concepts is discussed, and the original proposal is rejected. Drawing on insights developed throughout the paper, some suggestions are made as to how one should address the different requirements that theory and practice demand of the value taxonomy of professional codes of ethics.     

A negative order-repetition priming effect: inhibition of order in unattended auditory sequences?

A novel negative priming (NP) effect is reported in which serial recall for a sequence of visually presented digits was poorer if the same sequence was presented as an irrelevant auditory sequence on the previous trial (Experiments 1 and 2). The effect was enhanced when attention was divided between the to-be-repeated auditory sequence and the concurrent to-be-remembered (TBR) sequence (Experiment 3). When the TBR sequences were also presented auditorily, NP arose only when the repeated TBR sequence was in the same voice as the previous irrelevant sequence; a voice mismatch produced positive priming (Experiment 4). The results suggest that the order of auditory events is registered preattentively and that inhibition may be applied to the acoustic transitions between irrelevant events.     

Is the focus of attention in working memory expanded through practice?

This article reinvestigates the claim by P. Verhaeghen, J. Cerella, and C. Basak (2004) that the focus of attention in working memory can be expanded from 1 to 4 items through practice. Using a modified version of Verhaeghen et al.'s n-back paradigm, Experiments 1 and 3 show that a signature of a one-item focus, the time cost for switching between items in working memory, persists over practice. Verhaeghen et al. reported a shift over practice from a step function to a linear slope of reaction times over set size and argued that it reflects the expansion of the focus. With an improved counterbalancing scheme, a continuously increasing slope was found even without practice in Experiment 2. The results question the hypothesis that the focus is expanded through practice. They are in line with predictions from a model that distinguishes a one-item focus from a direct-access region holding about 4 items.     

Is social inhibition of return due to action co-representation?

When two individuals alternate reaching responses to visual targets presented on a shared workspace, one individual is slower to respond to targets occupying the same position as their partner’s previous response. This phenomenon is thought to be due to processes that inhibit the initiation of a movement to a location recently acted upon. However, two distinct forms of the inhibition account have been posited, one based on inhibition of an action, the other based on inhibition of an action and location. Furthermore, an additional recent explanation suggests the phenomenon is due to mechanisms that give rise to action congruency effects. Thus the three different theories differ in the degree to which action co-representation plays a role in the effect. The aim of the present work was to examine these competing accounts. Three experiments demonstrated that when identical actions are made, the effect is modulated by the configuration of the visual stimuli acted upon and the perceptual demands of the task. In addition, when the co-actors perform different actions to the same target, the effect is still observed. These findings support the hypothesis that this particular joint action phenomenon is generated via social cues that induce location-based inhibition of return rather than being due to shared motor co-representations.     

The Role of the Corpus Callosum in Interhemispheric Transfer of Information: Excitation or Inhibition?

The corpus callosum is the major neural pathway that connects homologous cortical areas of the two cerebral hemispheres. The nature of how that interhemispheric connection is manifested is the topic of this review; specifically, does the corpus callosum serve to communicate an inhibitory or excitatory influence on the contralateral hemisphere? Several studies take the position that the corpus callosum provides the pathway through which a hemisphere or cortical area can inhibit the other hemisphere or homologous cortical area in order to facilitate optimal functional capacity. Other studies suggest that the corpus callosum integrates information across cerebral hemispheres and thus serves an excitatory function in interhemispheric communication. This review examines these two contrasting theories of interhemispheric communication. Studies of callosotomies, callosal agenesis, language disorders, theories of lateralization and hemispheric asymmetry, and comparative research are critically considered. The available research, no matter how limited, primarily supports the notion that the corpus callosum serves a predominantly excitatory function. There is evidence, however, to support both theories and the possibility remains that the corpus callosum can serve both an inhibitory and excitatory influence on the contralateral hemisphere.     

Just Another Face in the Crowd? Distinctiveness Seeking in Sweden and Britain

Previous literature on the impact of culture on distinctiveness seeking shows diverging predictions and inconclusive results. We propose that this may be partly due to the fact that distinctiveness can be sought on various levels of awareness. We theorize that cultural values will influence explicit, intentional forms of distinctiveness seeking, but will not necessarily moderate the underlying strength of the identity motive for distinctiveness. Participants in the UK and Sweden completed a measure of cultural values and explicit and implicit measures of distinctiveness seeking. National differences were found in two explicit measures of distinctiveness seeking, and these were partially mediated by individual differences in value priorities. However, no difference was found in our implicit measure of the distinctiveness motive. These findings highlight the importance of attending to the multi-faceted and culturally flexible nature of identity motives.