What is the word memory test

Behavior

Measures Commonly Used to Assess Deficit

Memory Assessments

The term “working memory” refers to the short-term storage and manipulation of information (Baddeley, 1990). Neuropsychological tests that assess working memory include serial digit learning (Benton et al., 1994) and digit span backwards (Wechsler, 1987) tests. In contrast, memory for information that is retrieved after a longer time frame (e.g., over several days or years) is often referred to as long-term memory. Long-term memory can be further divided into declarative (explicit) and procedural (implicit) memory.

Episodic memory falls under the category of declarative long-term memory, and is most easily assessed with a long-delay recall trial from any word-list learning test such as the Hopkins Verbal Learning Test–Revised (Brandt & Benedict, 2001). This type of memory best discriminates persons with Alzheimer’s disease from cognitively normal older adults because a defining feature of the disease is rapid information loss after only brief delays. Once a person has dementia, however, severity cannot be measured with this type of assessment because episodic memory is impaired early in the disease course (Albert, 2008).

Semantic memory is also a form of declarative memory and refers to memory for meanings using general knowledge about the world. Semantic memory can be assessed through recognition tests such as the Portland Digit Recognition test (Binder, 1993) or the Word Memory Test (Green, Allen, & Astner, 1996). Because semantic memory, unlike episodic memory, does not decline with age (Craik, 1977; Zacks & Hasher, 2006), strategies that take advantage of such existing abilities may be easier for older adults to learn with training.

Procedural (implicit) memory is a type of long-term memory for skills such as riding a bicycle or typing on a keyboard that one may not consciously think about. Tests of procedural memory include the Implicit Association Task (Greenwald, McGhee, & Schwarz, 1998) and Lexical Decision Task (Meyer & Schvaneveldt, 1971).

Prospective memory is memory for future events, such as performing a task at a certain time (e.g., attending a doctor’s appointment on Tuesday, after lunch). Although prospective memory may be assessed fairly easily (such as by asking a patient to call your office in four days), validated assessments, such as the Cambridge Prospective Memory Test (Wilson et al., 2005), are also available.

Consideration of Table 8.1 is only the beginning of a clinician’s decision-making process about memory assessment. As some tasks are more burdensome and time-consuming than others, a clinician should consider how much time they have to allocate for assessments. For example, verbal memory tests such as the Auditory Verbal Learning Test (AVLT; Rey, 1941) or the California Verbal Learning Test (CVLT; Delis, Kramer, Kaplan, & Ober, 2000) have good psychometric properties (reliability, validity), and are well-established tests. However, they take longer to administer compared with the Hopkins Verbal Learning Test-Revised (HVLT-R; Brandt & Benedict, 2001). The HVLT-R also has well-established reliability and validity, and is well tolerated, even by significantly impaired individuals. Finally, it provides environmental support for memory through semantic categories that can serve as cues for memory recall.

Other Cognitive Assessments

In addition to assessing memory function, it is equally important to assess related cognitive constructs (e.g., attention, perception, language, executive functioning) as these abilities are often related to memory performance. Further, certain cognitive impairments can limit the options for memory training. For instance, many memory-training programs, such as the ACTIVE memory training intervention, focus on attention and concentration skills (Jobe et al., 2001). Therefore, an individual demonstrating pre-existing impairment in these cognitive domains may not have the skills and abilities to adhere to, or potentially benefit from, a memory training intervention (Cahn-Weiner, Malloy, Rebok, & Ott, 2003; Unverzagt et al., 2007).

Tests of attention are typically tasks that measure an individual’s ability to concentrate and sustain focus over time and ignore irrelevant stimuli. Examples include the Brief Test of Attention (Schretlen, 1989) and the Digit Symbol Substitution task (Wechsler, 1987). Low performance on such tasks implies problems with sustained attention. Such an impairment could obviously affect performance on other cognitive tasks, such as those involving memory. Patients with mild dementia show little impairment when given simple attention tasks like the Digit Span Forward test (Wechsler, 1987), but impairment is more apparent as tasks become increasingly more complex.

Tests of visuospatial or perceptual ability include the Pattern Comparison and Rey–Osterrieth Complex Figure Draw tasks (Osterrieth, 1944; Salthouse & Babcock, 1991). They test the mental capacity to remember or mentally manipulate visual and spatial stimuli, and deficits may suggest neurological injury, presence of dementia, or an agnosia of some sort (Colcombe & Kramer, 2003).

Tests of language ability, such as the Verbal Fluency Test (Harrison et al., 2000) or the Boston Naming Test (Kaplan, Goodglass, & Weintraub, 1983), assess the verbal production and expression of speech. Semantic and phonemic fluency are two types of fluency measured by the Verbal Fluency Test (Harrison et al., 2000). Semantic or category fluency is tested by giving the patient a semantic category upon which to draw, such as animals. Phonemic fluency taps into memory functions but also requires executive information processing functions to initiate and maintain systematic memory search strategies for information given an ambiguous cue. Both types of fluency are predictive of dementia (Chan, Butters, Salmon, & Maloney, 1993; Henry, Crawford, & Phillips, 2004).

Finally, executive abilities are a broad category of cognitive functions that encompasses cognitive control and coordination of multiple cognitive capacities (Duncan, Emslie, Williams, Johnson, & Freer, 1996). Examples include set-shifting and multi-tasking (Kramer & Madden, 2008; Salthouse, Hambrick, Lukas, & Dell, 1996), problem solving, inhibition (Metcalfe & Mischel, 1999; Salthouse & Meinz, 1995), and goal-directed behaviors like meal preparation and shopping (Kramer, Hahn, & Gopher, 1999; Kray, Eber, & Lindenberger, 2004).

3.2.1 Verbal memory

The California Verbal Learning Test (CVLT) (Delis et al., 1987), two Selective Reminding (SR) tasks (Buschke and Fuld, 1974) and 4 recall of word lists tasks were included in the analysis. The Warrington Recognition Memory task (Words) (Warrington, 1984) which tests the participant׳s ability to recognise a previously presented word when paired with a distractor was also included, as well as the paired associates and logical memory subscales of the Wechsler Memory Scale (WMS; Wechsler, 1987).

3.2.2 Visual memory

The Benton Visual Retention test (BVRT; Benton, 1945), Rey–Osterrieth Complex Figure test recall measure (RCFT; Rey, 1941), Visual Selective Reminding Test and Continuous Visual Memory Test (CVMT; Trahan and Larrabee, 1989) were included in this domain. Visual memory was also assessed using a non-standardised task in which an array of numbers was visually presented followed by immediate recall (Gordeev, 2008) and the visual reproduction subscale of the WMS (Wechsler, 1987). Visual recognition memory was investigated using 3 subtests of the computerised Cambridge Neuropsychological Test Automated Battery (CANTAB; Cambridge Cognition, Cambridge, UK) – Spatial Recognition, Pattern recognition and delayed match to sample and the Warrington Recognition Memory test (Faces) (Warrington, 1984).

3.2.3 Working memory

Working memory abilities were assessed using span and superspan tasks. The digit span task (Wechsler, 1981), the Hebb Digit Recurring task, the Corsi Block Tapping Task (CBTT; Berch, 1998) and the spatial span subtask of the computerised CANTAB (Cambridge Cognition, Cambridge, UK) were included in the analysis. These tasks are also influenced by attention and verbal and visual memory abilities.

3.2.4 Attention

Attention was assessed using the Digit Symbol task from the Wechsler Adult Intelligence Scale-Revised (WAIS-R; Wechsler, 1981), a Continuous Performance Test (Rosvold et al., 1956), time to complete the Trail Making Test part A (TMT A; Reitan, 1958), the Digit Vigilance task (Lewis and Rennick, 1979), the Rapid Visual Information Processing subtask of the CANTAB (Cambridge Cognition, Cambridge, UK) and the mental control task of the WMS (Wechsler, 1987).

3.2.5 Perception

Tests included in this section were classed primarily as tests of perception by Lezak et al. (2004) as they measure visual field perception, visual searching and facial recognition but also include selected and divided attention. The Benton Facial Recognition test (BFRT; Benton 1983) was used to test facial recognition in the absense of a memory condition. The Visual Field Neglect task from the ‘Testbatterie zur Aufmerksamkeitsprufung’ (TAP; Zimmermann and Finn, 1993) was used to test divided attention and the Signal Detection test from the Weiner Test System (Schuhfried, 1999), however information on psychometric properties could not be found for either of these measures. The Munsterberg test was also used to test selective attention. A Schulte tables task of sustained attention and a digit cancellation test were also used. The Munsterberg test requires participants to find words in a random set of letters within a limited time. Psychometric properties for the Munsterberg task and Schulte tables were not found in a search of the literature. Some literature was found indicating that Schulte tables do not have well established psychometric properties (Ennok, 2010).

3.2.6 Visuospatial ability

Visuospatial ability was assessed using the Block Design task from the WAIS-R (Wechsler, 1981), the copy trial of the RCFT (Rey, 1941), and an unstandardised Virtual Water Maze analog testing spatial orientation and learning (Jacobs et al., 1997). The ability to perform spatial rotations mentally was investigated using the mental rotation test (MRT; Vandenberg and Kuse, 1978).

3.2.7 Executive function

The category of executive functioning was expanded from that of Lezak et al. (2004) in line with Burgess (2003) to incorporate tests of inhibition, coordinated dual tasks (e.g. the Trail Making Task) and verbal fluency. In the context of the reviewed studies, such measures were used with the purpose of assessing executive functioning. Results were considered under the headings of planning and organising, set shifting, verbal fluency and decision making. The Wisconsin Card Sort Task (WCST; Heaton et al., 1993), time to complete the Trail Making Test part B (TMT B; Reitan, 1958), the Intradimensional–Extradimensional shift and the Spatial Working Memory subtasks of the computerised CANTAB (Cambridge Cognition, Cambridge, UK) were used to assess set shifting. The Tower of London subtask of the computerised CANTAB (Cambridge Cognition, Cambridge, UK) and the organisation trial of the RCFT (Rey, 1941) were used to assess planning and organising ability. Verbal fluency was assessed using the FAS letter fluency task (Benton and Hamsher, 1983), a category fluency task (Goodglass and Kaplan, 1983) and the Benton Controlled Oral Word Association Test (COWAT; Benton, 1989). Decision Making ability was examined by Cavedini et al. (2002) using the Iowa Gambling Task (IGT; Bechara et al., 1994), by Kaplan et al. (2006) using the Cambridge Gambling task (Rogers et al., 1999) and by Ludewig et al. (2003) using a two-choice prediction task (Paulus, 1997).