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Diploma thesis on “The Enhancement of Memory and Concentration via Audio-visual Stimulation with Optic-acoustic Systems”


At the Friedrich-Alexander University Erlangen-Nuremberg in January 2009, Viktor Wuchrer examined in an experimental survey the impact of audio-visual alpha- and beta frequencies induced by optic-acoustic systems regarding the enhancement of cognitive  performance. The results of his dissertation confirm a strong effect of the alpha treatment on memory and concentration. In addition, a strong effect of the beta treatment on concentration was verified, not, however, on memory. The experiment supports the repeatedly publicized findings about the effectiveness of audio-visual  stimulation via optic-acoustic systems regarding cognitive performance. Previous scientific research also confirmed the positive effects of optic-acoustic systems concerning relaxation and the activation of cognitive performance. The Frequency Following Response, on which optic-acoustic systems are based, therefore allows the conclusion that its active principle can be used – to some extent – for the regulation of mental states and a certain “readiness to learn”.

Participants: 104 students between the age of 18 and 41 were examined in a laboratory experiment.

Procedure: Two variations each of the sub-test “Gegenstände” (objects) from the “LGT-3” (Learning- and Memory Test) according to Bäumler (1974) were used for the capture of memory performance, hence additionally in parallel form A and B, eliminating memory effects in the follow-up test. In this memory test, the participants had to memorize 20 visual objects within one minute, in order to reproduce them unaided afterwards. The participants’ concentration was determined with the help of the “d2-Concentration Test” according to Brickenkamp (2002): They had to process 14 lines of 47 items each as well as distinguish correct symbols from incorrect ones and cross them out in order. For each line, exactly 20 seconds of processing time was given until all 14 lines had been attended to. The Synchro CD-ROM by brainLight® was applied for the technical treatment, whereby two specific programs with alpha- and beta frequencies, which - depending on the conditions of the test - were induced. In particular, a program with the constant frequency of 10 Hz was played for the alpha treatment and a program with 18 Hz for the beta treatment, each for the duration of 20 minutes. Instead of doing a session with the optic-acoustic system, the participants of the control group had to read the prose text of a guided meditation and write an essay about it, which comparatively served as the placebo treatment.

Results: Concerning the alpha treatment it proved to be true that participants who were specifically stimulated audio-visually with an alpha program of 10 Hz were able to reproduce significantly more items in the memory test (M = 1.73, SD = 2.38) compared to the control group without audio-visual stimulation (M = -.04, SD = 2.03). On  average, the alpha group remembered 1.7 memory items more in the follow-up test in comparison to the control group that hardly improved. With regards to the d2-Concentration Test, the former group also showed a significantly higher concentration rate (M = 69.44, SD = 26.19)  compared to the control group (M = 49.00, SD = 21.55). Accordingly, the alpha group processed on average 69 items after a brainLight® stimulation of 10 Hz versus the control group achieving only 49 items in the follow-up test. The test subjects for the beta treatment, however,  demonstrated a highly significant improvement of their concentration performance in the d2-Test (M = 72.50, SC = 19.88) compared to the control group (M = 49.00, SD = 21.55). Even though the beta group on average also reproduced more items than the control group in the  memory test, the divergence is below statistical significance.

Summary: The examinations at hand show that test subjects are generally more susceptive to new information and external stimuli of all kinds through the induction of an average alpha state of 10 Hz, which can therefore conduce to a learning environment, too. Hence, this state of mind could be connected to a kind of attentiveness that is slightly turned inwards for the absorption of information and at the same time still perceives all surroundings. Likewise, the alpha state subsequently contributes to a better reproduction of memory material. With regards to an activation induced by beta frequencies, explicit improvements of concentration and at processing external stimuli  become apparent, which also involves an attentiveness turned out-wards. This kind of mental activation that can be generated by using optic-acoustic systems, specifically through audio-visual stimulation, thus implies the possibility of regulating mental states. Consequently, the applicability to corresponding tasks can be deduced. Thus, beta frequencies (18 Hz) in particular would for example complement attentive and active processing of subject matter or enhance the motivation to learn, while average alpha frequencies (10 Hz) would support  memory performance and the absorption of new information.