Interpreting the orientation of objects: A cross-disciplinary review.

Is object orientation an inherent aspect of the shape of the object or is it represented separately and bound to the object shape in a similar way to other features, such as colour? This review brings together findings from neuropsychological studies of patients with agnosia for object orientation and experimental studies of object perception in healthy individuals that provide converging evidence of separate processing of object identity and orientation. Individuals with agnosia for object orientation, which typically results from damage to the right parietal lobe, can recognize objects presented in a range of orientations yet are unable to interpret or discriminate the objects' orientation. Healthy individuals tested with briefly presented objects demonstrate a similar dissociation: object identity is extracted rapidly in an orientation-invariant way, whereas processing the object's orientation is slower, requires attention and is influenced by the degree of departure from the canonical orientation.

Retrieval-induced forgetting with novel visual stimuli is retrieval-specific and strength- independent.

Retrieval-induced forgetting (RIF) is the phenomenon whereby remembering a subset of learned items can reduce memory for other related items. There are two main explanations for this effect: the competition account and the inhibition account. Most research to date has favoured the inhibition account, though two potential confounds have been identified in the evidence for key predictions of the account: (1) Using binary measures of accuracy may make it difficult to detect correlations between the magnitude of RIF and the increase in recall for practised items that is predicted by the competition account (strength dependence), and (2) typical non-competitive restudy may be too weak a form of practice to elicit detectible RIF effects.

Sharing the load: How a personally coloured calculator for grapheme-colour synaesthetes can reduce processing costs.

Synaesthesia refers to a diverse group of perceptions. These unusual perceptions are defined by the experience of concurrents; these are conscious experiences that are catalysed by attention to some normally unrelated stimulus, the inducer. In grapheme-colour synaesthesia numbers, letters, and words can all cause colour concurrents, and these are independent of the actual colour with which the graphemes are displayed.

Working memory load reduces corticospinal suppression to former go and trained no-go cues.

Environmental cues associated with an action can prime the motor system, decreasing response times and activating motor regions of the brain. However, when task goals change, the same responses to former go-associated cues are no longer required and motor priming needs to be inhibited to avoid unwanted behavioural errors. The present study tested whether the inhibition of motor system activity to presentations of former go cues is reliant on top-down, goal-directed cognitive control processes using a working memory (WM) load manipulation.

Working Memory in Pediatric Epilepsy: A Systematic Review and Meta-Analysis.

Working memory is a multicomponent system that is supported by overlapping specialized networks in the brain. Baddeley's working memory model includes four components: the phonological loop, visuo-spatial sketchpad, the central executive, and episodic buffer. The aim of this review was to establish the gravity and pattern of working memory deficits in pediatric epilepsy.

Repetition blindness for words and pictures: A failure to form stable type representations?

Repetition blindness (RB) is the failure to detect and report a repeated item during rapid serial visual presentation (RSVP). The RB literature reveals consistent and robust RB for word stimuli, but somewhat variable RB effects for pictorial stimuli. We directly compared RB for object pictures and their word labels, using exactly the same procedure in the same participants.

Substantiating synesthesia: a novel aid in a case of grapheme-colour synesthesia and concomitant dyscalculia.

Here we present the case of SP, a 21-year-old female with life-long dyscalculia. SP was subsequently diagnosed with grapheme-color synesthesia, a diagnosis that serendipitously catalyzed our development of a novel aid:The digit-color calculator (DCC). The DCC substantiates SP's color , dramatically ameliorating her difficulties with basic calculations.

Motor Memory: Revealing Conditioned Action Tendencies Using Transcranial Magnetic Stimulation.

can be elicited by motivationally salient stimuli (e.g., appetitive rewards) or objects that support utilization behaviors.

Binding identity and orientation in object recognition.

We tested whether an object's orientation is inherently bound to its identity in a holistic view-based representation at the early stages of visual identification, or whether identity and orientation are represented separately. Observers saw brief and masked stimulus sequences containing two rotated objects. They had to detect if a previously cued object was present in the sequence and report its orientation.

Semantic repetition blindness and associative facilitation in the identification of stimuli in rapid serial visual presentation.

Repetition blindness (RB) is the inability to detect both instances of a repeated stimulus during rapid serial visual presentation (RSVP). Prior work has demonstrated RB for semantically related critical items presented as pictures, but not for word stimuli. It is not known whether the type of semantic relationship between critical items (i.

The role of location in visual feature binding.

Location appears to play a vital role in binding discretely processed visual features into coherent objects. Consequently, it has been proposed that objects are represented for cognition by their spatiotemporal location, with other visual features attached to this location index. On this theory, the visual features of an object are only connected via mutual location; direct binding cannot occur.

Motor-evoked potentials reveal functional differences between dominant and non-dominant motor cortices during response preparation.

Transcranial magnetic stimulation (TMS) of the motor cortex produces motor-evoked potentials (MEPs) in contralateral muscles. The amplitude of these MEPs can be used to measure the excitability of the corticospinal tract during motor planning. In two experiments, we investigated learning-related changes in corticospinal excitability as subjects prepared to respond in a choice reaction-time task.

Automatic Recruitment of the Motor System by Undetected Graspable Objects: A Motor-evoked Potential Study.

Previous behavioral and neuroimaging studies have suggested that the motor properties associated with graspable objects may be automatically accessed when people passively view these objects. We directly tested this by measuring the excitability of the motor pathway when participants viewed pictures of graspable objects that were presented during the attentional blink (AB), when items frequently go undetected. Participants had to identify two briefly presented objects separated by either a short or long SOA.

Summary statistics in the attentional blink.

We used the attentional blink (AB) paradigm to investigate the processing stage at which extraction of summary statistics from visual stimuli ("ensemble coding") occurs. Experiment 1 examined whether ensemble coding requires attentional engagement with the items in the ensemble. Participants performed two sequential tasks on each trial: gender discrimination of a single face (T1) and estimating the average emotional expression of an ensemble of four faces (or of a single face, as a control condition) as T2.

Two scenes or not two scenes: The effects of stimulus repetition and view-similarity on scene categorization from brief displays.

Previous research suggests that understanding the gist of a scene relies on global structural cues that enable rapid scene categorization. This study used a repetition blindness (RB) paradigm to interrogate the nature of the scene representations used in such rapid categorization. When stimuli are repeated in a rapid serial visual presentation (RSVP) sequence (~10 items/sec), the second occurrence of the repeated item frequently goes unnoticed, a phenomenon that is attributed to a failure to consolidate two conscious episodes (tokens) for a repeatedly activated type.

Reconsidering Temporal Selection in the Attentional Blink.

Two episodes of attentional selection cannot occur very close in time. This is the traditional account of the attentional blink, whereby observers fail to report the second of two temporally proximal targets. Recent analyses have challenged this simple account, suggesting that attentional selection during the attentional blink is not only (a) suppressed, but also (b) temporally advanced then delayed, and (c) temporally diffused.

Visual field asymmetries in object individuation.

Repetition blindness (RB) is a failure to detect both instances of two identical stimuli presented in close temporal proximity. It is due to an inability to form separate episodic tokens for a repeated stimulus, resulting in a single conscious representation. In three experiments, participants identified two targets presented simultaneously in different spatial locations.

Attention is required for the perceptual integration of action object pairs.

Previous studies have demonstrated that functionally related objects are perceptually grouped during visual identification if they are depicted as if interacting with each other (Green and Hummel in J Exp Psychol Hum Percept Perform 32(5):1107-1119, 2006). However, it is unclear whether this integration requires attention or occurs pre-attentively. Here, we used a divided-attention task with variable attentional load to address this question.

Automaticity and cognitive control in the learned predictiveness effect.

In novel contexts, learning is biased toward cues previously experienced as predictive compared with cues previously experienced as nonpredictive. This is known as learned predictiveness. A recent finding has shown that instructions issued about the causal status of cues influences the expression of learned predictiveness, suggesting that controlled, volitional processes play a role in this effect.

The contextual action relationship between a tool and its action recipient modulates their joint perception.

Facilitatory effects have been noted between tools and the objects that they act upon (their "action recipients") across several paradigms. However, it has not been convincingly established that the motor system is directly involved in the joint visual processing of these object pairings. Here, we used the attentional blink (AB) paradigm to demonstrate privileged access to perceptual awareness for tool-action recipient object pairs and to investigate how motor affordances modulate their joint processing.

Repetition blindness reveals differences between the representations of manipulable and nonmanipulable objects.

We used repetition blindness to investigate the nature of the representations underlying identification of manipulable objects. Observers named objects presented in rapid serial visual presentation streams containing either manipulable or nonmanipulable objects. In half the streams, 1 object was repeated.

Disentangling the contributions of grasp and action representations in the recognition of manipulable objects.

There is an increasing evidence that the action properties of manipulable objects can play a role in object recognition, as objects with similar action properties can facilitate each other's recognition [Helbig et al. Exp Brain Res 174:221-228, 2006]. However, it is unclear whether this modulation is driven by the actions involved in using the object or the grasps afforded by the objects, because these factors have been confounded in previous studies.

When more is less: extraction of summary statistics benefits from larger sets.

Despite several processing limitations that have been identified in the visual system, research shows that statistical information about a set of objects could be perceived as accurately as the information about a single object. It has been suggested that extraction of summary statistics represents a different mode of visual processing, which employs a parallel mechanism free of capacity limitations. Here, we demonstrate, using reaction time measures, that increasing the number of stimuli in the set results in faster reaction times and better accuracy for estimating the mean tendency of a set.

Target sparing effects in the attentional blink depend on type of stimulus.

In a typical attentional blink (AB) experiment, recognition of the second of two serially presented targets is impaired if it occurs around 200-500 ms after the first. However, recognition for the second item is often intact if the two targets occur consecutively (lag-1 sparing). Recent theories of the AB have placed great emphasis on the presence of lag-1 sparing and protracted sparing effects, where accurate performance is seemingly maintained across three or more targets, provided that they are presented consecutively.