Cognitive therapy and brain training
Screening: Divided Attention
www.rehacom.com
Cognitive therapy and brain training by Hasomed GmbH
This manual contains information about using the RehaCom therapy system. Our therapy system RehaCom delivers tested methodologies and procedures to train brain performance . RehaCom helps patients after stroke or brain trauma with the improvement on such important abilities like memory, attention, concentration, planning, etc. Since 1986 we develop the therapy system progressive. It is our aim to give you a tool which supports your work by technical competence and simple handling, to support you at clinic and practice.
HASOMED GmbH Paul-Ecke-Str. 1 D-39114 Magdeburg Tel: +49-391-6107650 www.rehacom.com
Inhalt
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Inhaltsverzeichnis Teil I Applications
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Teil II Target group
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Teil III Structure
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Teil IV Implementation and Duration
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Teil V Data analysis
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Teil VI Bibliography
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Index
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Divided Attention
Applications Basic information on the screening you will find in the RehaCom manual, Chapter "Screening and Diagnostics". Divided Attention is the ability to pay attention to several things at the same time. The attention is therefore divided for simultaneous processes. In everyday life, this is the rule rather than the exception. Persons with deficits in this area often complain about huge problems of coping with everyday life. Attention resources must be divided between several, competing stimuli. Divided attention means the ability to perform several tasks/activities at the same time or alternate in short time periods. Colloquially, this ability is called multitasking.
Figure 1: irrelev ant stimulus, v isual stimulus
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Target group Attention disorders may occur in almost all neurological diseases, which affect the central nervous system. Depending on whether these diseases lead to rather circumscribed and localized brain damages (such as a stroke) or to rather diffused impairments (such as traumatic brain injury or degenerative diseases), the malfunction in the attention area can be rather specific or global.
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Target group
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Cerebrovascular Diseases After lesions in the brain stem portion of the formatio reticularis (Mesulam 1985) and after strokes, especially in the area of the median brain artery (A. cerebri media) of the right brain hemisphere, disorders of attention activation as well as the vigilance and the long-term maintenance of attention can occur (Posner et al. 1987). While the reticular system of the brain stem portion is the "noradrenergic source" of attention activation(Stuss u. Benson 1984), the frontothalamic "Gating-System" controls the selective and directed allocation of this attention activation. Lesions of this system lead to a limited selectivity for external stimuli and to increased distractibility, i.e. to disorders of the attention focus. Lesions especially of frontal parts of the left hemisphere, also cause impairments of attention selectivity, especially in situations, in which fast decisions between relevant and irrelevant aspects of a task have to be made (Dee u. van Allen 1973, Sturm u. Bussing 1986). Disorders of spatial attention can be selectively affected by localized brain damages. Damages of the posterior parietal lobe seem to lead especially to disorders of disengaging the attention off a stimulus, when the attention must be moved towards a target stimulus in the room half on the opposite side of the lesion (Posner et al. 1984). Here, a cause for a unilateral neglect after a parietal lesion is seen (see guidline "Rehabilitation of disorders of spatial cognition"). Disorders of divided attention seem to occur particularly often after bilateral frontal vascular damages (Rousseaux et al. 1996). Traumatic Brain Injury (TBI) Along with memory disorders, attention impairments are the most common neuropsychological deficits after a TBI. The most consistent result after TBI is a general, non-specific slowdown of the information processing. The cause of this malfunction after TBI remains largely unclear. As a pathological correlate of the damage due to the mainly rotational acceleration of the brain, "diffuse axonal damages" are discussed or a hypometabolism in prefrontal and cingulate brain areas (Fontaine et al. 1999). Multiple Scleroses Cognitive slowing and increased variability with an often preserved performance quality at the beginning of the disease is a widespread deficit in patients with multiple sclerosis, so that tests with reaction time measurement are of special significance in this disease. It is obvious, that this retardation relatively independent of the individual sub-functions of the attentional performance. As neuronal basis, a diffusely localized axonal damage and demyelination is assumed, whose counterpart a generally increased degree of brain atrophy could be proved (e. g. Lazeron et al. 2006).
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Divided Attention
Neurodegenerative Diseases Already at the early stage of Alzheimer- dementia (AD), attention deficits are often seen. They often seem to occur after memory disorders, but before impairments of language and spatial performances (Perry et al. 2000). Other results indicate a relative maintenance of the cognitive control of attention activation and visuo-spatial attention, but also early disorders of the selective attention. In the course of the disease, also disorders of the inhibitory control increase. In Lewy body dementia, fluctuating attention performances and deficits in the visuospatial attention are a central diagnostic criterion. Recent studies (Calderon et al. 2005) reported that clients showed significant worse results in almost all attention functions (sustained attention, selective attention, divided attention) compared to AD-patients. Patients with Parkinson's disease or Huntington's chorea generally show no deficits in phasic alertness and vigilance tasks, whereas patients with progressive supranuclear paralysis (Steele-Richardson-Olszewski-Syndrome) suffer from such disorders. Disorders of the divided attention seem to be a general problem in dementia diseases in later stages of diseases. Depression and Attention Disorders Even in case of depression, memory and attention disorders are to the fore of the cognitive functional impairments. Primarily, conscious cognitive controlled functions are affected. Especially the performance during tasks for the attention distribution has been identified as a prognostic parameter (Majer et al. 2004). Only in very severe depressions, disorders of automatic processing can be present (Hartlage et al. 1993). In comparison to e.g. patients after traumatic brain injury (TBI) depressed patients often estimate their performances worse than they actually are in the psychometric examination. Farrin et al. (2003) could show that this negative selfassessment, e.g during task for sustained attention, can lead to "disaster reactions" after mistakes with an enlarged reaction times immediately afterwards. TBI -patients did not show such reactions. Source: Leitlinien fĂźr Diagnostik und Therapie in der Neurologie; 4. revised edition, ISBN 978-3-13-132414-6; Georg Thieme Verlag Stuttgart
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Structure The subject has to work on a visual and an auditive task in parallel. Auditive - visual requirements
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Structure
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Visual task: In the center of the screen, a square field with 5 circles is displayed. All circles are open (figure 2). During task performance, the position of the openings changes. The position of the circles remains unchanged.
Figure 2: irrelevant stimulus
When a constellation with a closed circle is presented in the field (figure 3), the subject has to press the answer-button as fast as possible. Only one circle is always closed.
Figure 3: Relevant stimulus
Auditive task: Synchronously with each position change of the circle openings, the subject hears a high tone and a low tone. When the same tone sounds two times in a row, the subject has to press the answer button as fast as possible.
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Divided Attention
Implementation and Duration The screening starts with an exercise. It is considered as passed, when the subject reacted once to a relevant auditive as well as to a relevant visual stimulus. Afterwards, the actual screening starts. Five circles with openings at changing positions must be observed. When a circle is closed, the subject has to press the answer-button. Synchronously, high and low tones are presented alternatively. When the same tone sounds two times in a row, the subject has to press the answer-button.
Figure 4: Target stimulus: one circle completely closed
Figure 5: Non Target: all circles are open
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Implementation and Duration
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Duration 3 min (without practice)
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Data analysis Basic information on the data analysis of screening results you will find in the RehaCom manual, chapter "Results screening". In the screening Divided Attention, two Z-values are calculated. Z-values 1: Visual divided attention Standard value is the number of visual omissions, that means the number of missed reactions to a relevant visual stimulus. Z-values 2: Auditive divided attention Standard value is the number of auditive omissions, that means the number of missed reactions to two consecutive, identical acoustic stimuli. Details Detailed information on the course of the screening can be displayed via the button "Details". On the right side is a list of all conducted screenings for Divided Attention and their end times. Results marked with an asterisk (*) indicate that the particular screening was canceled. In this case, the evaluation is incomplete - e.g. no Z-values are indicated. The detailed analysis allows the presentation of a maximum of three results at the same time. The first and the last fully completed screening is preselected. One can change the selection by clicking the particular checkbox. The display in the diagrams changes accordingly. The background color of each result row corresponds to the line color in the diagram and the tab color in the summary.
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Divided Attention
The diagram "Reaction time" (fig. 6) shows all single reaction times on relevant stimuli. On the left side, all visual stimuli and on the right side all auditive stimuli are indicated. If the subject didn't react to a stimulus, no marker is set. Thus, a dotted line is shown. To accurately display a reaction time one can click on the square marker. The maximum and minimum reaction time of screening are displayed automatically.
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Data analysis
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The error diagram (fig. 7) all presented stimuli are used. On the left side, all visual stimuli and on the right side all auditive stimuli are indicated. Depending on the error, small bars are shown in different directions: Bar up (value 1): Reaction to irrelevant stimulus Bar down (value -1): No reaction to relevant stimulus Bar up (value 0.25): Anticipation of relevant stimulus In case of a reaction without presentation of a relevant stimulus, one can not decide to which type of stimulus (auditive or visual) the subject reacted. Therefore, an error is stored for each type of stimulus and many bars are displayed accordingly. If the subject reacted too late to a relevant stimulus, it is indicated in the error diagram in terms of a bar drawn downwards (for the missed stimulus) and two bars drawn upwards (for a reaction to irrelevant stimuli, one for a visual and one for an auditive stimulus).
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Divided Attention
On the tab "Summary" (fig. 8), further tabs are indicated for each selected result. On the tabs, the names of the Z-values, the achieved value, and the basic standard with the calculated Z-value are shown. The chart includes the mean value, the median, and the standard deviation of all reactions to relevant stimuli, separated by modality. In addition, the number of correct reactions (max. 13 for auditive, max. 14 for visual) as well as the number of omissions and outliers are included. Since incorrect reaction can be assigned clearly to a certain type of stimulus, they are only visible in the row "Total". Anticipation: If the reaction time is less than 100 ms. Outliers: Each reaction time, which lies over the mean reaction time plus the 2.35-times standard deviation.
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Bibliography Thöne-Otto, A., George, S., Hildebrandt, H., Reuther, P., Schoof-Tams. K., Sturm, W., & Wallesch, C.-W. (2010). Leitlinie zur Diagnostik und Therapie von Gedächtnisstörungen. Zeitschrift für Neuropsychologie, 21, 271-281. Lavie, N. & de Fockert, J.W. (2005). The role of working memory in attention capture. Psychological Bulletin and Review, 12, 669-674.
© 2014 HASOMED GmbH
Bibliography
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Lavie, N., Hirst, A. & de Fockert, J.W. (2004) Load theory of selective attention and cognitive control. Journal of Experimental Psychology: General, 133, 339-354 Sturm, W. (2002). Diagnostik von Aufmerksamkeitsstörungen in der Neurologie. Aktuelle Neurologie, 29, 25-29. de Fockert, J.W., Rees, G., Frith, C.D. & Lavie, N. (2001) The role of working memory in visual selective attention. Science, 291, 1803-1806. Pashler, H. & Johnston, J.C. (1998). Attention limitations in dual-task performance. In H. Pashler (Hrsg.), Attention, Hove: Psychology Press. Sanders, A.F. (1997). A summary of resource theories from a behavioral perspective. Biological Psychology, 45, 5-18. Rees, G. & Frith, C.D. (1997), Modulating irrelevant motion perception by varying attentional load in an unrelated task. Science, 278, 1616-1619. Allport, A.D. (1993). Attention and control: Have we been asking the wrong questions? A critical review of twenty-five years. In D.E. Meyer, S. Kornblum (Hrsg.), Attention and Performance XIV (183-218). Cambridge, MA: MIT Press. Lane, D.L. (1982). Limited capacity, attention allocation and productivity. In W.C. Howell & E.A. Fleishman (Hrsg.), Information processing and decision making. Hillsdale, NJ: Erlbaum. Julesz, B. (1981). Textons, the elements of texture perception and their interactions. Nature, 290, 91-97. Broadbent, D.E. (1958). Perception and Communication. New York: Pergamon Press. Leitlinien fur Diagnostik und Therapie in der Neurologie; 4. überarbeitete Auflage, ISBN 978-3-13-132414-6; Georg Thieme Verlag Stuttgart
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Divided Attention
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Index
-Llesions
-A-
1
-M-
alzheimer- dementia 1 answer-button 3, 5 anticipation 6 attention 1 auditive divided attention auditive task 3
marker 6 median 6 modality 6 multiple scleroses multitasking 1
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1
-N-
-B-
neurodegenerative diseases bars 6 bibliography
-O-
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-Ccerebrovascular diseases circles 5
outliers
data analysis 6 depression and attention disorders details 6 diagram 6 duration 5
error diagram 6 errors 6 evaluation 6 everyday life 1 exercise 5
-HHaken
3
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-P-
1
-D-
-E-
1
parallel 3 performance position 3 presentation 1
3 6
-Rreaction 6 reaction time results 6
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-Ssquare field 3 stimuli 1, 6 structure 3 subject 3, 5 summary 6
-Ttarget group task 3, 6
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Index tone 3 tones 5 total 6 traumatic brain injury
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-Vvigilance 1 visual divided attention visual task 3
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