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Sustained attention in language production

Suzanne Jongman and Gurupriya RamanathanDecember 17, 2014

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• Attention - an umbrella term comprising various types of abilities.

• Alerting - the ability to maintain alertness either briefly or over a prolonged period of time (sustained attention).

• Previous experiments - looked at components of attention such as executive control and have found evidence for a need for attention in early and late stages of production.

• Some studies have also investigated the role of sustained attention in language production in children (Spaulding et al., 2008; Duinmeijer, de Jong, Scheper, 2012).

• But what is the role of sustained attention in adults?

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Sustained attention

• CPT paradigm:– A type of vigilance task– Continuous presentation of numbers or letters– X/A-X– Measures include hits, omissions, false alarms,

vigilance decrement.

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Parameters affecting sustained attention

Event rate:• Jerison and Pickett (1964) first reported a threefold decrease in hit

rate when the event rate was increased from 5 events per minute to 30 events per minute.• Evidence for greater vigilance decrement also comes from Lanzetta

et al. (1987); Parasuraman and Davies (1976); and Warm & Jerison (1984).

• Parasuraman and Giambra (1991): Decrement in hit rate over time on task, specifically in the high event rate task.

• Ballard (2001): Faster reaction time and more omissions in the high event rate task than the low event rate task; increase in omissions over time on task.

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Previous studies

• Koelega (1992): More false alarms in the low event rate condition; reaction time and hits worsened over time on task.

• Participats respond faster but make more omission errors in conditions involving a higher event rate. But they take longer time to respond in tasks involving a lower event rate.

• Why? - The act of observing intermittent displays may be costly to attention.

- Inhibition of information-processing pathways (Posner, 1978).

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Current study

1. A picture-naming task designed to measure participants’ sustained attention ability in conjunction with language production.

2. A DDT in which performance can be correlated with that of the picture-naming task.

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Task 1• A picture-naming task

• 30 simple drawings of common objects with monosyllabic, high frequency Dutch names.

• Two conditions: high event rate and low event rate divided into four alternating blocks.

• Low event rate: 300 pictures presented for 1000ms with a 2s ISI (15 minutes).

• High event rate: 600 pictures presented for 1000ms with a 0.5s ISI (15 minutes)

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Predictions

High event rate

Will respond faster owing to the swift presentation of pictures but will make more naming errors.

There will also be a greater performance decrement.

Will take longer time to respond but with fewer naming errors

Low event rate

If language production requires sustained attention, then we should find performance impairments similar to the ones described in previous studies.

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Task 2

Digit discrimination task lasting 26.88 minutes:• Digits (0-9); target = 0.

• Two conditions - high event rate and low event rate divided into four blocks.

• Low event rate: 384 numbers presented for 100ms with a 2s ISI (13.44 minutes).

• High event rate: 1344 numbers presented for 100ms with a 0.5s ISI (13.44 minutes).

• The target was presented on 25% of all trials in each condition.

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Predictions

High event rate

Will respond faster but will make more omissions, fewer false alarm errors. There will be a

greater performance decrement over time on task

Will take longer time to respond but with fewer omissions, more

false alarm errorsLow event rate

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Analysis• 24 participants’ data:

– PN task: reaction times, hits, errors, misses, hesitations, performance decrement.

– DDT: reaction times, hits, misses, false alarms, performance decrement.

• Correlations between the reaction times and performance in both conditions for each task.

• Correlations between performance on each block across conditions in both tasks.

• T-tests on performance between blocks in both conditions in both tasks.

• Correlations between the performance decrement across both conditions in both tasks.

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Results• Picture-naming task:

High event rate condition (48 blocks=14400 trials)

Low event rate condition (48 blocks=7200 trials)

Prediction

Avg RT 725.44ms 752.91ms* PHits 14124 (98.08%) 7122 (98.92%)* POmissions 38 (0.26%) 18 (0.25%) X

Errors 130 (0.90%) 39 (0.54%)* PHesitations 108 (0.90%) 21 (0.29%)* PPerformance decrement

43.01ms 24.12ms X

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High vs. low event rate

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Performance in the picture-naming taskHigh event rate condition Low event rate condition

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Results

• DDT:High event rate condition (224 blocks=32256 trials)

Low event rate condition (64 blocks=9216 trials)

Prediction

Avg RT 408.96ms 449.44ms* PHits 7662/8064

(95.01%)2273/2304* (98.65%) P

Omissions 402/8064 (4.99%)

31/2304* (1.34%) P

False Alarms 138/24192 (0.57%)

43/6912 (0.62%)

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Performance decrement

17.05ms 21.26ms X

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High vs. low event rate

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Performance in the DDTHigh event rate condition Low event rate condition

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Performance decrement

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Predictions

High event rate Will respond faster owing to the swift presentation of pictures but

will make more naming errors

Will take longer time to respond but with fewer naming errorsLow event rate

High event rate

Will respond faster but will make more omissions, fewer false

alarm errors, greater performance decrement over

time on task

Low event rateWill take longer time to respond but with fewer omissions ,more

false alarm errors

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• Pictures may be slightly more stimulating than numbers.

• ISI not fast enough to tax production processes?

• Boredom/motivation

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and Experimental Neuropsychology, 23(2), 331-350.• Ballard, J. C. (1996). Computerised assessment of sustained attention: Interactive effects of task demand, noise, and anxiety. Journal of Clinical

and Experimental Neuropsychology, 18(6), 864-882.• Chee, P., Logan, G., Schachar, R. J., Lindsay, P., & Wachsmuth, R. (1989). Effects of event rate and display time on sustained attention in

hyperactive, normal, and control children. Journal of Abnormal Child Psychology, 17, 371-391.• Davies, D. R., & Parasuraman, R. (1982). The psychology of vigilance. London: Academic Press.• Jerison, H. J., & Pickett, R. M. (1964). Vigilance: The importance of the elicited observing rate. Science, 143, 970-971.• Koelega, H. S., Verbaten, M. N., van Leeuwen, T. H., Kenemans, J. L., Kemner, C., & Sjouw, W. (1992). Time effects on event-related brain

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Research Reviews, 35, 146-160.• Scerbo, M. W., Warm, J. S., Doettling, V., Parasuraman, R., & Fisk, A. D. (1987). Event asynchrony and task demands in sustained attention. In L.

S. Mark, J. S. Warm, & R. L. Houston (Eds.), Ergonomics and human factors: Recent research (pp. 33-39). New York: Springer-Verlag.• Spaulding, T., Plante, E., Vance, R. (2008). Sustained selective attention skills of preschool children with specific language impairment: Evidence

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London: Wiley.

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Thank you!