LOGO Age-Related Changes and the Attention Network Task: An Examination of Alerting, Orienting and, Executive Function JANINE M. JENINGS, DALE DAGENBACH, CHRISTINE M. ENGLE AND LAURA J. FUNKE Reporter: Ko-Da Tseng 01.18.2008
Outline 1 2 3 4 Introduction Methods Results Discussion
Introduction (1/17) Attention often plays an important role in theories of cognitive aging (Hasher & Zacks, 1979) Relationship between aging and attention remains somewhat inconclusive (Craik & Byrd, 1982)
Introduction (2/17) As one recent review of the literature on aging and attention noted (Rogers, 2000, p. 69) Aspects of attention that remain intact for older adults are: selective, focused, divided, and the transition from attention-demanding to automatic processes. Aspects of attention that decline for older adults are: selective, divided, and the transition from attention-demanding to automatic processes..... Some types of attention do show age-related declines, some types do not, and some types show declines only in certain contexts.
Introduction (3/17) Attention (selective vs. divided, for example) may be distinct from one another in whole or in part Age-related effects may indeed vary between them Discrepancies between studies Age on those nonattentional processes The attention & aging literature is beset It s difficulty in distinguishing between agerelated slowing & attentional processes
Introduction (4/17) Salthouse (1985, 1994) has made a case A generalized age-related decline in processing speed However, Other researchers have argued (Salthouse et al., 1995; Kramer & Larish, 1996; Tsang & Shaner, 1998) There are additional aspects of task impairment that are not due to slowing Even processing speed is controlled (Madden & Whiting, 2004) Problems of interpretation remain
Introduction (5/17) Posner and Peterson (1990) who identified three different aspects of attention The first network Alerting: frontal & parietal regions of the right hemisphere
The second network Introduction (6/17) Orienting: areas of the frontal & parietal lobes, including the superior parietal lobe & the temporal-parietal junction For example, superior parietal lobe activation has been found in relation to orienting using fmri (Corbetta et al., 2000)
The third network Introduction (7/17) Top-down executive control: anterior cingulate and dorso-lateral prefrontal cortex Activations of these areas have been found in Stroop-like tasks involving cognitive conflict (Pardo et al., 1990; Bench et al., 1993; Carter et al., 1995) 綠 紅
The Posner spatial cuing task Introduction (8/17) A peripheral cue, such as flashing the placeholder for the stimulus A central cue such as an arrow pointing to the stimulus location Participants to indicate the location of a target item
The Eriksen flanker task Introduction (9/17) Compared to a no-flanker condition, responses are faster Faster when the flanker are in the same category Slower when they are from the opposite one
Introduction (10/17)
Introduction (11/17)
Introduction (12/17)
Introduction (13/17) The following results suggest that the orienting network is unaffected by age With peripheral cues, a similar time course of cuing effects was observed and the old and young adults showed similar costs & benefits of invalid vs. valid cues (Hartley et al., 1990) With central cues produced like patterns (Folk and Hoyer, 1992) No age differences associated with peripheral cues in a letter-discrimination task (Greenwood et al., 1993)
Flanker interference effects Introduction (14/17) Older adults were less affected by the presence of flankers (Wright and Elias, 1979) Older adults>younger adults at close ranges of target-flanker separation, but not at further ones (Zeef et al., 1996)
Introduction (15/17) A clever variant of the flanker paradigm was used by Naylor and Lavie (1998) Participants searched a central circular array of a letter N for a target item. A interference X. The number of letters in the array varying.
Introduction (16/17) The magnitude of the flanker effect Six items: Old = Young 1 to 4 items: Old>Young Only 1 item: Old>Young
Introduction (17/17) Alerting deficits in Alzheimer s patients Only a marginally significant difference between younger and healthy older adults (Tales et al. 2002) Phasic alertness to be unaffected by both healthy aging and mild-to-moderate Alzheimer s disease (Nebes and Brady, 1993)
Methods (1/5) Participants 123 from two different age groups took part Old: 63 (28 females, 35 males) age from 61 to 87 Wake Forest University alumni Young: 60 (35 females, 25 males) age from 18 to 21 an introductory psychology pool
Materials Methods (2/5) The Attention Network Task (ANT) consisted of two sets of 96 trails IBM A20 laptop computer Participants seated 60 cm from the screen Participants pressed a key indicating whether an arrow Presented above or below a fixation cross shown in the center of the screen Pointing to the left or right
Materials (Con d) Methods (3/5) The arrow appeared with one of three different types of flankers Congruent arrows (32 times) Incongruent arrows (32 times) Neutral dashes (32 times) one of four types of cues (24 times) (24 times) (24 times) (24 times)
Methods (4/5)
Procedure Older Methods (5/5) Mini-Mental Status Examination (MMSE) The general health questionnaire Young The general health questionnaire To ensure the instructions were clear 20 practice trails
Results (1/6) The ANT allows one to examine three types of attention Alerting No-Cue vs. Double-Cue Orienting Center-Cue vs. Spatial-Cue Executive function Incongruent vs. Congruent
Results (2/6) Mean Reaction Times & Accuracy Age (no Sig.)
Results (3/6) Alertin, Orienting, and Executive Control 779-757 572-529 769-728 538-500 842-722 600-503 (Sig.) Old weaker alerting (no Sig.) Old & Young similar (Sig.) Old (120>98) greater negative impact
Results (4/6) Z-score Transformations to Correct for Generalized Slowing Z-score=X-X / Sx = 每 一 分 數 與 算 術 平 均 數 差 值 / 標 準 差 Older.170.329.899 Young.411.375.637 Sig. no Sig. no Sig.
Cue by Flanker Interaction Results (5/6) >85 >123 >122 >103 Alerting: Cong effect > Incong effect 653-605=48 > 378-727=11
Results (6/6) >85 >123 >122 >103 Orienting: Incong effect > Cong effect 740-688=52 > 617-582=35
Discussion (1/9) Use of ANT to compare the attentional processes of alerting, orienting, and executive function simultaneously between young and older adults yielded significant age (Fan et al., 2002) The intact operation of the orienting network with age is consistent with a body of literature (Folk & Hoyer, 1992; Greenwood et al., 1993; Hartley et al., 1990; Lincourt et al., 1997) Older adults benefit as much as young by peripheral spatial cues
Discussion (2/9) When the data were not adjusted for overall speed (before Z-score) The incongruent flankers had a greater impact on older participants than their younger counterparts Perhaps less able to inhibit the context surrounding the target stimulus Z-score transforming the data to correct Age differences in speed abolished the age flanker interaction Implying the increased effect of interference was an artifact of cognitive slowing
Discussion (3/9) Phasic alerting is unaffected by aging (Nebes & Brady, 1993; Rabbit, 1984) However, more recent studies have identified an age-related decline (Festa-Martino et al., 2004; Pate et al., 1994) Festa-Martino et al. (2004) suggest this discrepancy in the literature is caused by methodological differences
Discussion (4/9) A recent experiment using a modified version of the ANT task (Fernandez- Duque, & Black, 2006) Fernandez-Duque and Black their alerting cue for 500 msecs A similar mix of cue types as used here found a significantly larger alerting effect in older adults Longer cue durations (500 vs. 100 msecs) may result in increasing alerting effects in older adults
Discussion (5/9) Phasic alerting increases in older adults when the warning cue is presented for 750 msec (Sano et al., 1995) Use of a fish version of the ANT task with children (Rueda et al., 2004)
Discussion (6/9) Use of a fish version of the ANT task with children (Rueda et al., 2004) (Con d) Alerting effects 10-year-old children > adults Orienting effects Age 6 to adulthood (no difference) Executive function Differ only between the ages of 6 to 7
Discussion (7/9) Orienting cues affected executive function Decreasing RT to incongruent flankers A smaller flanker effect Alerting cues increased the flanker effect Reducing RT to congruent flankers When invalid spatial cue trials are included (Callejas et al., 2004) The process of alerting has even been shown to accelerate orienting
Discussion (8/9) Aging seems to have little impact on orienting and executive function beyond general slowing A 100-msec alerting cue on performance A smaller alerting effect in older adults This effect is due to age-related changes in the noradrenergic system (Elrod et al., 1997; Peskind et al., 1995)
Discussion (9/9) Successful use of the ANT with older adults With a cognitive neuroscience approach for exploring changes in attention with age Combining ANT with fmri
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