diff --git a/matlab/test/test_fiff_read_tag.m b/matlab/test/test_fiff_read_tag.m
index 3d7df1d..7a31f66 100644
--- a/matlab/test/test_fiff_read_tag.m
+++ b/matlab/test/test_fiff_read_tag.m
@@ -6,6 +6,6 @@
 function test_fiff_read_tag_()
 % Test fiff_read_tag.m
 %
-% This is just a placeholder file, referencing the below test function,
+% This is a placeholder function, referencing the below test function,
 % which should fail if fiff_read_tag does not work properly
 test_fiff_open
diff --git a/matlab/test/test_fiff_read_tag_info.m b/matlab/test/test_fiff_read_tag_info.m
index 79e5f08..328b22c 100644
--- a/matlab/test/test_fiff_read_tag_info.m
+++ b/matlab/test/test_fiff_read_tag_info.m
@@ -6,6 +6,6 @@
 function test_fiff_read_tag_info_()
 % Test fiff_read_tag_info.m
 %
-% This is just a placeholder file, referencing the below test function,
+% This is a placeholder function, referencing the below test function,
 % which should fail if fiff_read_tag_info does not work properly
 test_fiff_open
diff --git a/matlab/test/test_fiff_readwrite.m b/matlab/test/test_fiff_readwrite.m
index f6504fc..7165010 100644
--- a/matlab/test/test_fiff_readwrite.m
+++ b/matlab/test/test_fiff_readwrite.m
@@ -4,7 +4,15 @@
     initTestSuite;
 
 function test_fiff_readwrite_raw_()
-% Test a round trip of reading and writing raw data 
+% Test a round trip of reading and writing raw data
+%  this function calls the following relevant m-files:
+%   - fiff_read_meas_info
+%   - fiff_setup_read_raw
+%   - fiff_read_raw_segment
+%   - fiff_start_writing_raw
+%   - fiff_write_int
+%   - fiff_write_raw_buffer
+%   - fiff_finish_writing_raw
 
 FIFF = fiff_define_constants;