Cue‐locked lateralized components in a tactile spatial attention task: Evidence for a functional dissociation between ADAN and LSN

Abstract

Citation: Gherri, E., Gooray, E. & Forster, B. (2016). Cue-locked lateralized components in a tactile spatial attention task: Evidence for a functional dissociation between ADAN and LSN. Psychophysiology, 53(4), pp. 507-517. doi: 10.1111/psyp.12596 This is the accepted version of the paper.This version of the publication may differ from the final published version. Permanent Author NotesThe study was conducted in the Cognitive Neuroscience Suite of the University of Edinburgh and the authors would like to thank Shyla Hossain and Chrysa Retsa for their help with data collection. 2 AbstractERP studies investigating the control processes responsible for spatial orienting in touch have consistently observed that the anterior directing attention negativity (ADAN) elicited by an attention directing cue is followed by a sustained negativity contralateral to the cued hand.Recent evidence suggested that the later negativity, labelled late somatotopic negativity (LSN), might reflect distinct neuro-cognitive processes from those associated with the ADAN. To investigate the functional meaning of the ADAN and LSN components, we measured eventrelated brain potentials elicited by bilateral tactile cues indicating to covertly shift tactile attention to the left or right hand. Participants performed two spatial attention tasks which differed only for the difficulty of the target/nontarget discrimination at attended locations. The LSN but not the ADAN was sensitive to our experimental manipulation of task difficulty, suggesting that this component might reflect sensory-specific preparatory processes prior to a forthcoming tactile stimulus.Running Head: Cue-locked lateralized components in tactile attention tasks

Electrophysiological evidence for changes in attentional orienting and selection in functional somatic symptoms

“…In contrast to the ADAN, we expected a group difference in the presence of the LSN, a marker more closely linked to somatic sensory processing. In line with previous research from our group ( Gherri and Forster, 2012 , Gherri et al, 2016 ), the LSN was present 200 ms before target onset with an enhanced negativity over central and anterior electrodes contralateral to the cue. Although this component might appear as a continuation of the ADAN, it has been shown to be functionally different and independent of the ADAN, reflecting somatic rather than external coding of space (see Gherri and Forster, 2012 for an in-depth discussion).…”

“…Baseline correction was performed to the 100 ms period preceding the onset of the cue. To investigate lateralised effects of attention, three time intervals were analysed; ADAN (400–600 ms), LDAN (600–800 ms) and LSN (900–1100 ms), in line with previous studies ( Gherri et al, 2016 , Jones and Forster, 2012 ). Each time interval was analysed separately with mixed-factors ANOVA including the between-subject factor Group (high vs low SDQ-20 score), and within-subject factors Region (Regions where the presence of lateralized ERP components has been previously reported: anterior, central vs posterior), Hemisphere (contralateral vs ipsilateral to the cue location) and Electrode (21/34, 37/49 vs 22/33 corresponding to F3/4, F7/8 vs FC5/6 for anterior regions; 17/11, 31/24 vs 47/39 corresponding to C3/4, CP5/6 vs T7/8 for central regions; and 44/42, 45/41 vs 29/26 corresponding to P3/4, P7/8, O1/2 for posterior regions).…”

“…Participants then respond to a target presented at an attended or unattended location, thus providing a measure of shifts of attention. During the orienting of attention to a body location following the onset of the cue, a sequence of lateralized components are usually reported over anterior and central electrode sites ( Forster et al, 2009 , Gherri and Forster, 2012 , Gherri et al, 2016 , Jones and Forster, 2012 ). First, the Anterior Directing Attention Negativity (ADAN) is seen as an enhanced negativity contralateral to the attention directing cue elicited around 400–600 ms after cue onset.…”

“…This Late Somatosensory Negativity (LSN) is characterised by an enhanced negativity contralateral to the side attention is oriented. The LSN has been suggested to reflect sensory specific preparatory processes prior to target onset as it is modulated by tactile target discriminability ( Gherri et al, 2016 ), and, furthermore, it was shown to be diminished when attention is divided between vision and touch ( Jones and Forster, 2013b ). Thus, we hypothesised that this latter component may be modulated in somatoform disorder, if, as it has been suggested, the mechanisms underlying attentional orienting to the body are altered (c.f.…”

New Evidences: React Faster to Auditory and Tactile Spatial Targets of the Congenitally Blind

“…Hearing is the first sense on which bind people relay in getting information than other senses, as hearing enables the blind to get information through verbal communication and keeps the person in contact with social and physical phenomena in his environment, but as for communicating with physical environment, hearing efficiency diminishes and decreases to a significant extent, people may or may not speak [9].…”