2111 Attention L5.pptx

Selective Attention 5 (PS2011) Dr. Doug Barrett e-mail:[email protected] Selective Attention Selective attention is essential to guided behaviour Deficits in attention compromise everyday tasks Core feature of psychopathology: – Lesions – ADHD – Schizophrenia PS2011 Hemispatial Neglect Neurological syn...

Selective Attention 5 (PS2011) Dr. Doug Barrett e-mail:[email protected] Selective Attention Selective attention is essential to guided behaviour Deficits in attention compromise everyday tasks Core feature of psychopathology: – Lesions – ADHD – Schizophrenia PS2011 Hemispatial Neglect Neurological syndrome associated with unilateral cortical lesions Affects approximately 2/3 of acute right hemisphere stroke patients Presents as a lack of awareness of objects and events contralateral (opposite) the causal lesion PS2011 Hemispatial Neglect RH Lesion: Neglect – no Negle Voxelwise statistical comparis Karnath et al. 2004 PS2011 Mort et al. 2003 Diagnostic Tests of Visual Neglect Hemispatial Neglect Deficits in neglect provide a window on attention and spatial representation Spatial coordinates (position) can be coded relative to the: – – – PS2011 The individual’s centre of gaze (retinotopic) An object’s central axis (e.g. midline) Other objects in the scene (alocentric) Hemispatial Neglect Left side of space or left side of the object? PS2011 Hemispatial Neglect Driver & Halligan, 1991 (cited in Ward, 2015) Patient failed to detect differences on left side of image that fell on the right side of visual midline PS2011 Hemispatial Neglect Spatial deficits in hemispatial neglect appear to operate in multiple (and dissociable) coordinate systems Magnitude of neglect is also effected by non-spatial stimulus attributes PS2011 Emotion and Extinction Domingues-Borras et al, 2012 (Review) PS2011 Emotion and Extinction Unilateral Bilateral Neutral Bilateral Negative Neural correlates of extinction and awareness for neutral and negative facial expressions (Vuillumier et al. 2002) PS2011 Emotion and Extinction Unilateral Bilateral Neutral Bilateral Negative Amygdala Fearful - Neutral Region of Interest (ROI) Perceived - Extinguished PS2011 Emotion and Extinction PS2011 Hemispatial Neglect Deficits associated with extinction and neglect reflect physical damage to neural circuits Extinction reflects relative activation rather than absence of response to visual stimulus Attentional not perceptual deficit PS2011 Attention and Psychopathology Deficits in attention also characterise many psychiatric syndromes Inhibitory deficit (of irrelevant stimuli) core feature of Schizophrenia and ADHD PS2011 Selective Attention & Schizophrenia Cellard e al. (2007) Task Irrelevant PS2011 Dot-Task Dot-Task 5 4 1 2 1 4 2 3 1 3 5 Dot-Task Dot-Task 5 4 1 2 3 1 2 3 5 4 Dot-Task Perceptual Array 2R objects Selecti on VWM Selecti on VWM 5 R objects Selective Attention & Schizophrenia PS2011 Attention and Psychopathology SZ group had significantly reduced memory span Reduction attributed to a deficit in selective attention – failure to prioritise relevant perceptual items for maintenance in VWM PS2011 Selective Attention & ADHD ADHD is a developmental disorder associated with impulsivity and impaired attentional control Central deficits of sustained attention and response inhibition These have been attributed to disrupted fronto-striatal circuits (see Booth et al. 2005) PS2011 Selective Attention & ADHD Individuals with ADHD: – Have reduced prefrontal volumes compared to controls – Show reduced activation in frontal and cingulate regions Inhibition of irrelevant information and pre-potent responses crucial for goal-directed behaviour PS2011 Selective Attention & ADHD Rubia et al. (2005) used fMRI to contrast neural activation during response inhibition and error detection in ADHD Sampled 16 medication-naïve adolescents with ADHD and age-matched healthy controls PS2011 Adaptive Procedure 50% correct threshold PS2011 Adaptive procedure (staircase) used to equate difficulty of the task across participants Kingdom & Prins (2010) Psychophysics: a practical introduction. London: Academic Press. Selective Attention & ADHD ADHD group Slower to respond on go trials Faster to respond on stop trials Made more errors of omission Had more variable RTs PS2011 Selective Attention & ADHD PS2011 PS2011 Selective Attention & ADHD Data reveal differential activation of neural circuits associated with attentional control in ADHD Reduced activation of prefrontal cortex and anterior cingulate during successful inhibition Reduced activation of cingulate cortex when inhibition fails Cingulate cortex associated with dynamic allocation of attention (flexibility) PS2011 Selective Attention & ADHD Evidence of altered neurophysiological function despite task difficulty being equated and lack of medication in ADHD group Changes in neural activation correlated with parental ratings of children on the Strengths and Difficulties Questionnaire ADHD characterised by distinct pattern of activity across network of cortical areas associated with attention and control PS2011 Summary Attention coordinates competitive neural process in order to guide coherent behaviour Selective attention entails a network of neural areas that prioritise and schedule sensory and post-sensory processes Deficits of attention are a core characteristic of many types of psychopathology Patterns of inattention in neuropsychological and pathological patients provide insights into the role of attention in “normal” individuals PS2011 Testing your understanding… Imagine you have been asked to investigate whether emotion mediates inhibition on a test of visual short-term memory in schizophrenia 1. What stimuli would you use? 2. How would you manipulate 1. Emotional valence? 2. Visual short-term memory load? 3. What would you measure (what is your D.V.?) PS2011 Further reading: Any cognitive text book that includes a chapter on attention References in the lecture: 1. Cellard, C., et al. (2007). Brain and Cognition, 64: 201-207. 2. Carter, J. D., et al. (2010). Schizophrenia Research, 122: 104112. 3. Karnath, H-O., et al. (2004). Cerebral Cortex, 14: 1164-1172. 4. Mort, D., et al. (1998). Brain, 126: 1986-1997. 5. Vuilleumier, P., et al. (2002). Neuropsychologia, 40: 2156-2166. 6. Dominguez-Borras, J., et al. (2012). Neuropsychologia, 50: 1054-1071. 7. Rubia, K., et al. (2005). American Journal of Psychiatry, 162: 1067-1075. PS2011