NEUROPSYCHOLOGICAL ASSESSMENT LAB

PAUL JONES, ED.D.
UNIVERSITY OF NEVADA, LAS VEGAS

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REVISED NORMS:

Assessment Lab Report 2-3
December/1998

This report provides summary data on characteristic response patterns of upper division teacher education students on selected ANAM/TWB instruments with the addition of data obtained in the series two studies. The intent is to provide baseline data for use in future studies, enhancing the capability to use the instruments in placement decisions and to isolate treatment effects. Demographic information about series one and series two participants is available in related reports. Related reports are also available with descriptions of the series one test instruments and series two instruments.

The format of this report is intended to provide sufficient detail for future investigators to replicate the test conditions. For the ANAM/TWB scales used in this test series, this report includes:

1. a description of the response conditions
2. summary statistics for accuracy and efficiency scores
3. identification of score levels which may be clinically significant

Accuracy is defined as the percentage of correct responses. Efficiency is the number of correct responses per minute. Because accuracy scores on the ANAM/TWB scales are typically high, the efficiency score is likely to be more useful in most applications.

Calculation of the clinical significance levels is based on procedures suggested by Gastaldo, Reeves, Levinson, and Wenger (1997) and by Kay (1995). Scores in the range between the 5th and 15th percentile are identified as suggesting moderate impairment. Scores below the 5th percentile are identified as suggesting significant impairment.

Normative data for the Simple 2-Choice Reaction Time scale are based on participants in the series two studies (n=71). Normative data for Procedural Reaction Time, Mathematical Processing, Spatial Processing, and Matching to Sample scales include participants from both series one and series two. Practice conditions were different in the series one and series two studies, but a study found no significant effect of the time-delay and single-occasion practice conditions on performance in the actual test trials. Data from participants in both series are thus combined in the norms below (n=123). Normative data for the two Sternberg scales not included in the series two studies are available in the prior report.

The data below are for actual test trials. In each case, the test trial has been preceded by a brief practice session for orientation.

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SIMPLE 2-CHOICE REACTION TIME: Standard Stimuli

Stimuli are presented on the screen for up to 8000 ms with a maximum of 9000 ms allowed for response. The test trial has 30 stimuli (items).

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TABLE 1
SIMPLE 2-CHOICE REACTION TIME
n=71

	accuracy percent	efficiency score
mean	97.3	131.1
s.d.	4.62	16.52
median	98.3	131.7
maximum	100.0	169.6
minimum	66.7	62.4
75%ile	100.0	140.0
25%ile	96.7	123.1
moderate impairment	90 to 93	105 to 117
significant impairment	0 to 89	0 to 104

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PROCEDURAL REACTION TIME: Standard Stimuli

Stimuli are presented on the screen for up to 8000 ms with a maximum of 9000 ms allowed for response. The test trial has 37 stimuli (items).

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TABLE 2
PROCEDURAL REACTION TIME-Standard Stimuli
n=123

	accuracy percent	efficiency score
mean	98.1	103.8
s.d.	3.43	11.77
median	100.0	105.6
maximum	100.0	125.1
minimum	83.3	60.9
75%ile	100.0	112.6
25%ile	96.7	96.1
moderate impairment	90 to 95	85 to 88
significant impairment	0 to 89	0 to 84

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PROCEDURAL REACTION TIME: Degraded Stimuli

The task demand was identical to the standard stimulus condition, but stimuli on the screen were visually distorted and more difficult to identify. Stimuli are presented on the screen for up to 8000 ms with a maximum of 9000 ms allowed for response. The test trial has 37 stimuli (items).

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TABLE 3
PROCEDURAL REACTION TIME-Degraded Stimuli
n=123

	accuracy percent	efficiency score
mean	98.3	99.4
s.d.	2.75	16.96
median	100.0	101.0
maximum	100.0	131.8
minimum	86.7	50.6
75%ile	100.0	111.4
25%ile	96.7	90.6
moderate impairment	93 to 95	66 to 80
significant impairment	0 to 92	0 to 65

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MATHEMATICAL PROCESSING

Math problems using sets of three single-digit numbers, e.g., 5+3-4 = ? are displayed on the screen. The subject determines whether the answer is greater than or less than five, responding by clicking the left or right mouse button. Stimuli are displayed for up to 14900 ms with 15000 ms allowed for response. The test trial has 25 stimuli (items).

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TABLE 4
MATHEMATICAL PROCESSING
n=123

	accuracy percent	efficiency score
mean	92.8	24.1
s.d.	8.13	6.16
median	96.0	23.6
maximum	100.0	42.4
minimum	52.0	9.6
75%ile	100.0	28.3
25%ile	92.0	19.8
moderate impairment	76 to 87	14 to 16
significant impairment	0 to 75	0 to 13

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SPATIAL PROCESSING: Simultaneous

Two histograms are displayed simultaneously on the monitor. The histogram on the right is rotated. The subject indicates with click of left or right mouse button whether the two histograms are identical in shape. Stimuli are displayed for up to 8000 ms with up to 9000 ms allowed for response. The test trial has 25 items.

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TABLE 5
SPATIAL PROCESSING-Simultaneous
n=123

	accuracy percent	efficiency score
mean	92.7	29.8
s.d.	9.28	7.47
median	96.0	29.6
maximum	100.0	52.5
minimum	52.0	10.7
75%ile	100.0	34.8
25%ile	89.0	24.2
moderate impairment	76 to 87	19 to 20
significant impairment	0 to 75	0 to 18

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MATCHING TO SAMPLE

A single 4 by 4 matrix with cells of red and yellow is displayed on the screen. The subject initiates the presentation of the test stimulus by clicking a mouse button. The test stimulus consists of two 4 by 4 matrices, side by side on the screen, one of which is identical to the previously presented standard stimulus. The subject clicks the left or right mouse button to identify the identical stimulus. Stimuli are displayed for up to 14900 ms with 15000 ms allowed for response. The test trial has 25 items.

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TABLE 6
MATCHING TO SAMPLE
n=123

	accuracy percent	efficiency score
mean	88.9	32.2
s.d.	9.76	9.74
median	92.0	31.2
maximum	100.0	62.9
minimum	56.0	11.4
75%ile	96.0	37.1
25%ile	84.0	25.2
moderate impairment	68 to 75	18 to 22
significant impairment	0 to 67	0 to 17

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COMPARISON WITH OTHER SAMPLES

Table 7 below provides data for comparison with other sample groups. The information in Table 7 must be interpreted with a great deal of caution. Neither conditions of administration nor actual stimuli were identical with those used in this study. These data, thus, provide only a rough estimate of comparable performance.

The group identified as USMC was comprised of 197 (83 females and 114 males) United States Marine Corps recruits (Gastaldo, Reeves, Levinson, & Wenger, 1997). The age range was 17 to 26 with an average age of 18. The average number of years of education was 12.

The group identified as UOk was comprised of 64 male subjects from the University of Oklahoma and 15 male subjects from Wright State University (Schlegel, Gilliland, & Crabtree, 1992). The age range was 18 to 36 with an average age of 21. Approximately one-half were lower division students. Cognitive efficiency scores were not available for this sample

The group identified as TBI was comprised of 22 patients (11 male and 11 female) participating in a traumatic head injury rehabilitation program (Levinson & Reeves, 1997). All had sustained traumatic brain injuries, most from motor vehicle accidents. The ages ranged from 18 to 64 with an average of 38. The average number of years of education was 13. Data from three groups classified according to severity of injury (marginal-mild: n=8), mild-moderate: n=7), and moderate: n=7) were combined in Table 7.

Considering the caution noted above about lack of identical administration conditions, the data in Table 7 are essentially as would be anticipated, including high accuracy scores of the nonclinical groups. As anticipated, the TBI group had significantly lower accuracy and efficiency scores. In each instance the reported score for the TBI group met the criteria for classification as impaired in the tables above.

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TABLE 7
COMPARISON WITH OTHER SAMPLES

	UNLV				USMC				UOk			TBI
	Accuracy	Efficiency			Accuracy	Efficiency			Accuracy			Accuracy	Efficiency
react-1	98	104			n/a	n/a			98			92	86
react-2	98	99			n/a	n/a			96			n/a	n/a
math	93	24			93	21			98			80	12
spatial	93	30			90	24			n/a			87	15
match	89	32			91	37			n/a			n/a	n/a

Accuracy: percentage of correct responses
Efficiency: correct responses per minute

react-1: Procedural Reaction Time- Standard Version
react-2: Procedural Reaction Time- Degraded Stimuli
math: Mathematical Processing
spatial: Spatial Processing- Simultaneous
match: Matching To Sample

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References

Gastaldo, E., Reeves, D., Levinson, D., & Wenger, C.B. (1997). ANAM normative data: USMC-1995 hyponatremia outbreak studies. San Diego, CA: National Cognitive Recovery Foundation.

Levinson, D.M., & Reeves, D.L. (1997). Monitoring recovery from traumatic brain injury using Automated Neuropsychological Assessment Metrics (ANAM V1.0). Archives of Clinical Neuropsychology, 12, 155-166.

Kay, G. (1995). Cogscreen: Aeromedical edition: professional manual. Odessa, FL: Psychological Assessment Resources, Inc.

Schlegel, R.E., Gilliland, K., & Crabtree, M.S. (1992). Development of the UTC-PAB Normative Database: Technical Report. Springfield, VA: National Technical Information Service.

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Guide to Reports

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