Multinomial processing tree

Schweickert (1993) attempted to model memory redintegration using a multinomial processing tree.^[4] In a multinomial processing tree, the cognitive processes and their outcomes are represented with branches and nodes, respectively. The outcome of the cognitive effort is dependent on which terminal node is reached.^[3]

In Schweickert's model of recall, a trace of memory can be either intact or partially degraded. If the trace is intact, memory can be restored promptly and accurately. The node for correct recall is reached, and the recall process is terminated. If the memory has partially degraded, the item must be reconstructed through trace redintegration. If the process of redintegration was successful, the memory is recalled correctly.^[4]

Thus, the probability of correct recall (${\displaystyle P_{C}}$) is:

$${\displaystyle P_{C}=I+R*(1-I)}$$

Where:

${\displaystyle I}$ is the probability of trace being intact, and ${\displaystyle R}$ is the probability of correct redintegration.

If the trace is neither intact nor successfully completely redintegrated, person fails to accurately recall the memory.^[4]

Extensions

Schweickert's model was extended by Gathercole and colleagues (1999), who added a concept of degraded trace.^[6] Their model of the multinomial processing tree included an additional node, which represents a decayed memory. Such degraded trace can no longer undergo redintegration, and the outcome of recall is incorrect.^[3] Thus, the probability of correct recall (${\displaystyle P_{C}}$) changes to:

$${\displaystyle P_{C}=I+R*(1-I-T)}$$

Where:

${\displaystyle I}$ is the probability of trace being intact, ${\displaystyle R}$ is the probability of correct redintegration, and ${\displaystyle T}$ is the probability of trace being entirely lost.

Lexicality

In immediate recall, trace reconstruction is more accurate for words than for non-words.^[3] This has been labeled the lexicality effect. The effect is hypothesized to occur due to the differences in the presence and availability of phonological representations. Contrarily to non-words, words possess stable mental representations of the accompanying sounds. Such representation can be retrieved from previous knowledge, facilitating the redintegration of item from the memory trace. The lexicality effect is commonly used to support the importance of long-term memory in the redintegration processes.^[3]

Item similarity

The redintegration of memory traces may be affected by both semantic and phonological similarity of items which are to be recalled.^[3][7]

Redintegration is more accurate for lists of semantically homogenous items than for lists of semantically heterogeneous items. This has been attributed to the differences in the accessibility of different memories in the long-term store. When words are presented in semantically homogenous lists, other items may guide the trace reconstruction, providing a cue for item search. This increases the availability of certain memories and facilitates the redintegration process.^[3] An example would be a redintegration attempt for a word from a list of animal names. The semantic consistency of words evokes the memories associated with this matter, making the animal names more accessible in the memory.

Contrarily, redintegration has been shown to be hindered for items sharing phonological features. This has been attributed to the “trace competition”, where errors in redintegration are caused by mistaking the items on the lists.^[7] This effect could arise for example for the words auction (/ˈɔːkʃ(ə)n/) and audience (/ˈɔːdiəns/). The effect of phonological similarity on redintegration may differ depending on the position of phenomes shared within the items.^[7]

Word frequency

Redintegration processes appear more accurate for words that are encountered more frequently in the language.^[8] This effect has been attributed to the differences in the availability of items stored in long-term memory. Frequently encountered words are hypothesized to be more accessible for subsequent recall, which facilitates the reconstruction of memory redintegration of the partially degraded trace.^[8]

Phonotactic frequency

Trace reconstruction appears more accurate for items that contain phoneme combinations frequently represented in the language.^[6] Though this effect is similar to the word-frequency effect, it can also explain patterns in redintegration of non-word items.

Others

Other factors which have been shown to facilitate redintegration include the ease of item imageability,^[3] familiarity with the language,^[3] and word concreteness.^[8]