Closing-in behaviour and motor distractibility

Does high state anxiety exacerbate distractor interference?

Attentional Control Theory states that anxiety can cause attention to be allocated to irrelevant sources of information by hindering the ability to control attention and focus on the information that matters. In a separate line of inquiry, action-centred views of attention state that non-target distractors involuntarily activate response codes that may cause interference with target-directed movements (distractor interference effect). Due to the proposed negative effects of anxiety on attentional control, we examined whether anxiety could also modulate distractor interference. Participants executed target-directed aiming movements to one of three targets with the potential of a distractor being presented at near or far locations. Distractors were presented at different times with respect to the target presentation in order to explore the excitatory (0, -100 ms) and inhibitory (-850 ms) processing of the distractor. As a broad indication of the effect of anxiety, the analysis of no distractor trials indicated a lower proportion of time and displacement to reach peak velocity under high compared to low anxiety conditions. Meanwhile, the typical excitatory influence of the distractors located near, compared to far, at a short distractor-onset asynchrony was found in movement time and overall response time. However, this distractor excitation was even greater under high compared to low anxiety in the reaction time component of the response. These findings broadly implicate the attentional control perspective, but they further indicate an influence of anxiety on the excitation rather than inhibition of responses.

Closing-In Behavior and Motor Distractibility in Persons with Brain Injury

OBJECTIVE

This study investigates closing-in behavior (CIB), a phenomenon observed in graphic copying tasks when responses encroach upon or overlap the model. The behavior is most common amongst individuals with dementia and amongst pre-school children. We explored the relationship between CIB and the 'distractor effect' in reaching, whereby salient visual stimuli can influence the spatial trajectory of the reach.

METHOD

A group of individuals with overlap-CIB (n = 9), without CIB (n = 9) and healthy controls (HC; n = 6) underwent a task-irrelevant and a task-relevant distractors and the deviation of the movement trajectory towards the distractor location was measured in both tasks.

RESULTS

Individuals with graphic CIB showed more distractor-directed veering during reaching than did individuals without CIB or HC, provided that the distractor was relevant for the reaching task.

CONCLUSIONS

These results strengthen the relationship between CIB and the distractor effect and reinforce the hypothesis that CIB represents a disinhibited tendency to act towards the focus of attention.

Closing-in Behavior and Parietal Lobe Deficits: Three Single Cases Exhibiting Different Manifestations of the Same Behavior

Closing-in behavior (CIB) is observed in copying tasks (graphic or gestural) when the copy is performed near or on the top of the model. This symptom has been classically considered to be a manifestation of constructional apraxia and is often associated with a visuospatial impairment. More recent work emphasizes the attentional and/or executive nature of the behavior and its association with frontal lobe dysfunction. We describe three patients in whom CIB was associated with posterior parietal deficits of different etiologies (stroke in Patient 1 and dementia in Patients 2 and 3). In copying figures, Patient 1 produced the shape with high accuracy but the rendering overlapped the model, while for Patients 2 and 3 the copies were distorted but overlapping or in close proximity to the target. In gesture imitation, Patient 2 performed the gestures toward the examiner's space, while Patient 1 showed a peculiar form of CIB: when he was asked to place the ipsilesional arm in a position that mirrored the contralesional hand, Patient 1 moved his hand toward his contralesional hand. Patient 3 did not present gestural CIB. While CIB in Patient 1 was associated with selective deficits in executive functions and attention, additional visuospatial deficits were observed in Patients 2 and 3. The latter two patients showed a general visuoconstructional deficit. These case studies support a primary attentional account of CIB but also suggest that visuoconstructional impairments may contribute to the emergence of CIB, in some subjects. This evidence argues for different types of CIB with different cognitive and neural underpinnings. Furthermore, the data support the hypothesis of a differential involvement of fronto-parietal network in CIB.

The Closing-In Phenomenon in an Ecological Walking Task

OBJECTIVES

Alzheimer's disease (AD) patients may show the Closing-in (CI), a tendency to reproduce figures close to or superimposed on the model. AD patients with CI might manifest reduced functional independence compared to AD patients without CI, but no study directly assessed if CI can hamper common daily living activities. To address this issue here we investigated whether AD patients with CI veer their walking trajectory toward irrelevant objects more often than AD patients without CI.

METHODS

Fifty AD individuals, and 20 age- and education-matched healthy adults, underwent a graphic copying task to detect CI and a newly developed walking task to assess the tendency to veer toward irrelevant objects and to bump into them. All participants also completed a comprehensive neuropsychological battery to assess dementia severity; impairments in frontal/executive, visuo-spatial, visuo-constructional, and memory domains; and functional independence in daily living activities.

RESULTS

Graphic CI occurred in 34/50 (68%) AD patients (AD-CI group) who achieved significantly lower scores on frontal/executive abilities, and daily living functioning than AD individuals not showing CI. Most AD-CI patients (20/34; 58.8%) also showed at least one veering error in the walking task. Participants with CI and veering errors showed significantly poorer performance on Stroop test, and lower level of functional independence than AD individuals with CI in isolation.

CONCLUSIONS

CI on graphic tasks can identify difficulties in walking and in complying with everyday activities in AD patients. These observations demonstrate the value of assessing CI in copying tasks. (JINS, 2018, 24, 437-444).

The attraction of emotions: Irrelevant emotional information modulates motor actions

Emotional expressions are important cues that capture our attention automatically. Although a wide range of work has explored the role and influence of emotions on cognition and behavior, little is known about the way that emotions influence motor actions. Moreover, considering how critical detecting emotional facial expressions in the environment can be, it is important to understand their impact even when they are not directly relevant to the task being performed. Our novel approach was to explore this issue from the attention-and-action perspective, using a task-irrelevant distractor paradigm in which participants are asked to reach for a target while a nontarget stimulus is also presented. We tested whether the movement trajectory would be influenced by irrelevant stimuli-faces with or without emotional expressions. The results showed that reaching paths veered toward faces with emotional expressions, in particular happiness, but not toward neutral expressions. This reinforces the view of emotions as attention-capturing stimuli that are, however, also potential sources of distraction for motor actions.

Look where you're going! Perceptual attention constrains the online guidance of action

Action guidance, like perceptual discrimination, requires selective attention. Perception is enhanced at the target of a reaching movement, but it is not known whether selecting an object for perception reciprocally prioritises it for action. Two theoretical frameworks, the premotor theory and the Visual Attention Model, predict that this reciprocal relation should hold. We tested the influence of perceptual attention on the online control of reaching. In Experiment 1, participants attended covertly to a flanker on one or other side of a fixated target, prior to reaching for that target, which occasionally jumped, after reach onset, to the attended or non-attended side. Participants corrected their reaches for almost all target jumps. In Experiment 2, we required covert monitoring of the flanker during reaching. This concurrent perceptual task globally reduced correction behaviour, indicating that perception and action share a common attentional resource. Corrections were especially unlikely toward the attended side. This is explained by assuming that perceptual attention primed an action toward the attended location and that the participant inhibited this primed action. The data thus imply that perceptual selection constrains online action guidance, as predicted by the premotor theory and the VAM. We further argue that the fact that participants can inhibit a location within the action system but simultaneously maintain its prioritisation for perceptual monitoring, is easier to reconcile with the VAM than with the premotor theory.

Frontal defects contribute to the genesis of closing-in in Alzheimer's disease patients

Closing-in (CI) refers to copying drawings near to or superimposed on the original model, and is often observed in Alzheimer's disease (AD) patients. Contrasting hypotheses have been suggested to explain CI, but no prospective study has directly verified these interpretations. We evaluated the role of frontal/executive versus visuo-spatial impairments in a prospective sample of AD patients, and also explored whether different types of CI are related to specific neuropsychological tasks. We enrolled 64 AD patients who underwent copying tasks and an extensive neuropsychological assessment of visuo-spatial and visuo-constructional skills, frontal/executive abilities and anterograde memory. AD patients with CI showed more severe impairment on frontal/executive functions than AD patients without CI. Moreover, the tendency to produce copies superimposed on the model was selectively associated with poor inhibitory control for irrelevant responses. On this basis, we suggest that different CI phenomena could be ascribed to distinctive frontal/executive defects.

Inducing closing-in phenomenon in healthy young adults: the effect of dual task and stimulus complexity on drawing performance

Closing-in (CI) is the tendency to act very close to the model in tasks such as drawing, 3D construction, gesture imitation, or writing. Closing-in is observed in degenerative and focal brain diseases, but also in normally developing children. In the present paper, three experiments were conducted to evaluate whether CI can be triggered during a copying task in normal young adults by increasing stimulus complexity and attentional load. Participants were required to copy complex lines in one of three conditions: without interfering activities (baseline), during counting, or during execution of a 2-back short-term memory task. In Experiment 1, participants were required to reproduce horizontally aligned stimuli, starting from a dot placed below each stimulus and proceeding from left to right; in Experiment 2, stimuli were again horizontally aligned, but the starting dot was placed above each stimulus, and writing proceeded from right to left; in Experiment 3, stimuli were aligned vertically and copying proceeded in upward direction. Results from all experiments showed that when normal young adults are engaged in an attentional-demanding concurrent activity, they tend to approach to the model, whereas the effect of stimulus complexity disappeared with unusual writing direction (Experiments 2 and 3). These findings demonstrate that even in normal young adults, a reduction in available attentional resources can release an attraction toward the model.