Phase I: Phase I participants will engage in two sets of activities: (a) standardized and informal language and cognitive measures and (b) a series of language and cognitive activities performed during the collection of event related potential (ERP) recordings. Standardized language measures will include the: (a) Test of Adolescent/Adult Word Retrieval, (b) Cognitive Linguistic Quick Test, and (c) California Verbal Learning Test. Informal measures will include a conversational interaction about a participant's language difficulties and a topic of his/her choosing. During the conversational interaction, participants will press a button each time they experience difficulty retrieving a word.
ERPs measure electrical signals from the brain using a soft net of woven electrodes placed on a participant's head. Before the session, the investigators will soak a net in a saline (salt water) solution. The recording electrodes will be placed on the participant's scalp. The investigators will record ERPs while the participant completes the following tasks:
1. word retrieval: The participant will view a series of neutral stimuli (i.e., pictures of familiar objects, people, or locations flashed briefly on a computer monitor). The participant will press one of three buttons to indicate (a) recall of the name of the depicted image, (b) knowledge of the name but inability to recall it, or (c) no knowledge of the name of the depicted image. If a participant does not press a button within the time limit of the stimulus presentation, a new stimulus trial will begin. During some trials, participants will perform a second task requiring judgment about the orientation of lines appearing after the stimulus image. Following completion of all trials, the investigators will present the stimulus images a second time along with three response options: (a) the correct name, (b) an incorrect name, and (c) "don't know." The participant will again use a button press to indicate his/her response choice.
2. stimulus categorization: The participant will view a series of objects. For each object, he/she will categorize the stimulus semantically (e.g., Is the object a fruit or animal?) or phonologically (e.g., Does the object start with the letter "L" or "N?"). Participants will respond by pushing a button.
3. deductive reasoning: The participant will view written word pairs. Some of the pairs will relate to a specific word (e.g., "desert" and "humps" relate to "camel"), whereas other pairs will not (e.g., "desert" and "bark"). The participant will press one of two buttons to indicate whether a word pair triggers or does not trigger recall of a related word.
Phase II: Only people with acquired brain injury (ABI) will participate in Phase II activities. Phase II participants will attend two-hour, group intervention sessions one day per week for eight weeks. Participants will engage in multiple word game activities throughout each intervention session. Games will include Facts in Five, Anomia, Boggle, and Bananagrams as well as variations on these, as appropriate. Data collection during these sessions will be limited to a list of activities in which a participant engaged and the duration of engagement in each activity. Game-based group activities such as these are not typically used in intervention sessions for people with ABI who experience mild word-retrieval challenges. In fact, because of the subtlety of word retrieval difficulties experienced by people with relatively good recoveries from ABI--that is, the target population for this research--most people do not receive any treatment for this problem.
Phase III: Only people with ABI who have performed both Phase I and Phase II activities will be eligible for participation in Phase III. Following completion of the intervention sessions, participants will perform post-testing activities. Post-testing activities will include a subset of Phase I testing activities. Specifically, we will repeat (a) the audio recording of a conversational interaction and (b) the ERP recording with the same tasks used in Phase I.
