Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Differing roles for the dominant and non-dominant hands in the hand laterality task
AU - Ni Choisdealbha, Aine
AU - Brady, Nuala
AU - Maguinness, Corrina
PY - 2011/5
Y1 - 2011/5
N2 - Determining the handedness of visually presented stimuli is thought to involve two separate stages—a rapid, implicit recognition of laterality followed by a confirmatory mental rotation of the matching hand. In two studies, we explore the role of the dominant and non-dominant hands in this process. In Experiment 1, participants judged stimulus laterality with either their left or right hand held behind their back or with both hands resting in the lap. The variation in reactions times across these conditions reveals that both hands play a role in hand laterality judgments, with the hand which is not involved in the mental rotation stage causing some interference, slowing down mental rotations and making them more accurate. While this interference occurs for both lateralities in right-handed people, it occurs for the dominant hand only in left-handers. This is likely due to left-handers’ greater reliance on the initial, visual recognition stage than on the later, mental rotation stage, particularly when judging hands from the non-dominant laterality. Participants’ own judgments of whether the stimuli were ‘self’ and ‘other’ hands in Experiment 2 suggest a difference in strategy for hands seen from an egocentric and allocentric perspective, with a combined visuo-sensorimotor strategy for the former and a visual only strategy for the latter. This result is discussed with reference to recent brain imaging research showing that the extrastriate body area distinguishes between bodies and body parts in egocentric and allocentric perspective.
AB - Determining the handedness of visually presented stimuli is thought to involve two separate stages—a rapid, implicit recognition of laterality followed by a confirmatory mental rotation of the matching hand. In two studies, we explore the role of the dominant and non-dominant hands in this process. In Experiment 1, participants judged stimulus laterality with either their left or right hand held behind their back or with both hands resting in the lap. The variation in reactions times across these conditions reveals that both hands play a role in hand laterality judgments, with the hand which is not involved in the mental rotation stage causing some interference, slowing down mental rotations and making them more accurate. While this interference occurs for both lateralities in right-handed people, it occurs for the dominant hand only in left-handers. This is likely due to left-handers’ greater reliance on the initial, visual recognition stage than on the later, mental rotation stage, particularly when judging hands from the non-dominant laterality. Participants’ own judgments of whether the stimuli were ‘self’ and ‘other’ hands in Experiment 2 suggest a difference in strategy for hands seen from an egocentric and allocentric perspective, with a combined visuo-sensorimotor strategy for the former and a visual only strategy for the latter. This result is discussed with reference to recent brain imaging research showing that the extrastriate body area distinguishes between bodies and body parts in egocentric and allocentric perspective.
KW - Motor imagery
KW - Mental rotation
KW - Hand laterality task
KW - Handedness
KW - Laterality judgment
U2 - 10.1007/s00221-011-2652-9
DO - 10.1007/s00221-011-2652-9
M3 - Journal article
VL - 211
SP - 73
EP - 85
JO - Experimental Brain Research
JF - Experimental Brain Research
SN - 0014-4819
IS - 1
ER -